Spun-dyed, crimped polylactic acid fiber, method for manufacture thereof, and carpet

ABSTRACT

A spun-dyed textured polylacted filament yarn according to the present invention comprises a textured polylacted filament yarn, wherein the textured polylacted filament yarn includes a filament having an approximately circular or circular cross-section and has a relative viscosity of 2.5 to 3.8, wherein the textured polylacted filament yarn contains a coloring agent in an amount of 0.01 to 3 mass %, and wherein the textured polylacted filament yarn is 1.75 to 3.5 cN/dtex in tenacity, 35 to 60% in elongation, 500 to 3,500 dtex in total fineness, 2.5 to 25 dtex in a filament fineness, 2 to 8% in hot water shrinkage ratio, and 5 to 25% in dry heat crimp ratio. By employing the above structure, a spun-dyed textured polylacted filament yarn excellent in loftiness, toughness and abrasion resistance can be obtained. It is preferable that the cross-section of the filament has a degree of deformation less than 1.5, the degree of deformation being expressed by a ratio (B/A) of a diameter B of an circumscribed circle of the filament cross-section to a diameter A of a inscribed circle of the filament cross-section.

TECHNICAL FIELD

The present invention relates to a spun-dyed textured polylactedfilament yarn excellent in bulkiness, toughness and abrasion resistance,and the production method thereof. It also relates to a carpetconstituted by the textured filament yarns, which has sufficientvoluminous look and is excellent in texture and abrasion resistance.

In this specification, the wording of “spun-dyed textured syntheticfilament yarn” is used as an interpretation of the word which does notinclude a spun-dyed textured polylacted filament yarn.

BACKGROUND TECHNIQUE

Polylactide polymer is a biodegradable resin made from lactide obtainedfrom amylum of, e.g., corn and can be decomposed into water and carbondioxide by microorganisms, etc. Therefore, it has attracted attention asan earth-conscious material matching the natural global materialcirculation. Using polylacted filament yarns made from biodegradableresin, it has been considered to produce an option carpet for vehicles,a house roll carpet or rug, etc. If the same properties as those of acurrently available nylon textured filament yarn, polypropylene texturedfilament yarn or polyester textured filament yarn can be obtained usingfilament yarns made from polylactide resin, it can be expected toprovide wide variety of materials including, e.g., interior materials aswell as carpet materials.

A conventional carpet using textured polylacted filament yarns, however,has such drawbacks that it lacks bulkiness, it is easily worn away andit is easily buckled. Because of these drawbacks, such a carpet has verylimited practical usages. This is because the filament yarn propertiesand crimp characteristics, such as, e.g., tenacity or elongation, of thetextured polylacted filament yarn are inferior to those of the currentlyavailable nylon textured filament yarn, polypropylene textured filamentyarn and polyester textured filament yarn.

On the other hand, as to a textured polylacted filament yarn and theproduction method thereof, Patent Documents 1 to 3 have been publiclyknown. Patent Document 1 discloses that it is possible to suppressdeterioration of tenacity and/or crimp characteristic due to dyeing byusing a yarn-dyeing textured polylacted filament yarn having tenacity, acrimping extension ratio, a crimping latescent ratio and a tenacityretention ratio after a pressure hot-water treatment falling withinspecified ranges.

Furthermore, Patent Document 2 discloses that a carpet having softness,bulkiness and refreshing unique texture can be provided by employing atextured polylacted filament yarn having rectangle cross-section made ofpolylacted filament yarns in which an ellipticity of a cross-section ofa filament calculated from the ratio of the major axis of the filamentto the minor axis thereof is 3 to 8 and the filament has a filamentfineness of 5 to 25 dtex.

Furthermore, Patent Document 3 discloses that it is possible to improvethe bulkiness, abrasion resistance and buckling resistance of a carpetby employing a spun-dyed textured polylacted filament yarn made offilaments in which a deformed cross-sectional filament has a degree ofdeformation of 1.5 to 5.5 and the filament yarn has relative viscosity,tenacity, a textured extension ratio, a textured latescent ratio, anentangled number, and a entangled point tenacity each falling within aspecified range.

A conventional carpet using textured polylacted filament yarns and theproduction method thereof are disclosed in Patent Document 4, PatentDocument 5 and Patent Document 6.

In Patent Document 4, it discloses that the purpose is to “provide atufted carpet base fabric which causes no problem in natural environmentwhen discarded and a tufted carpet using the base fabric.” As the meansfor solving problems, it discloses that “the tufted carpet base fabricis constituted by long-filament yarn nonwoven fabric made of polylacticacid series copolymer, this carpet has a structure in which pile yarnsmade of polylactic acid series copolymer are tufted in the base fabric,and the backing material is made from biodegradable material.” ThisPatent Document describes a tufted carpet in which properties, such as,e.g., the lateral cross-sectional configuration of long-filament yarnnonwoven fabric, the crystallinity, are specified and that the pile yarnfor use in the carpet and the backing material are specified bypolylactic acid series copolymer and a material having biodegradability,respectively.

In Patent Document 5, it discloses that the purpose is to “provide acarpet which is in harmony with the environment and hasbiodegradability.” As the means for solving problems, it discloses a“carpet using biodegradable filament yarns having bulkiness preferablyused as a carpet and biodegradability as piles, and biodegradablematerials as a base fabric and backing materials.” This Patent Documentdescribes a biodegradable carpet in which the pile filament yarns, thebase fabric and the backing film are specified using fatty acidpolyester, especially polylactic acid.

In Patent Document 6, it discloses that the purpose is to “provide acarpet which can be easily disposed since, e.g., it will naturallydecompose and disappear in the ground when landfilled, generate noharmful gas when incinerated and is low in combustion heat. As the meansfor solving problems, it discloses a “polylactic acid resin filamentyarns are used as filament yarns for, e.g., piles and ground yarn andfabric such as, e.g., a base fabric and a back fabric, and polylacticacid resin compositions is used as an adhesive resin layer for joiningthe base fabric and the back fabric.” This Patent Document describes acarpet in which the filament yarns and fabrics are made of polylactedresin filament yarns and the adhesive agent is made of polylactic acidresin compositions.

Patent Document 1: Japanese Unexamined Laid-open Patent Publication No.2005-8997 Patent Document 2: Japanese Unexamined Laid-open PatentPublication No. 2005-48303 Patent Document 3: Japanese UnexaminedLaid-open Patent Publication No. 2005-60850 Patent Document 4:Republished PCT Patent Publication WO 00/65140 Patent Document 5:Japanese Unexamined Laid-open Patent Publication No. 2002-248047 PatentDocument 6: Japanese Unexamined Laid-open Patent Publication No.2003-10030 DISCLOSURE OF THE INVENTION Problems to be Solved by theInvention

However, the textured polylacted filament yarn disclosed in PatentDocument 1 relates to a yarn-dyeing textured polylacted filament yarn.The yarn-dyeing textured polylacted filament yarn assuredly deterioratesin tenacity, elongation and crimping characteristics by a pressurehot-water treatment for dyeing. Especially, in the case of dark colordyeing represented by black color dyeing, it is inevitable to executethe dying treatment with high-temperature hot-water (e.g., 120 to 130°C.), which causes remarkable deterioration of the properties.Accordingly, in cases where a dark color carpet is formed using texturedpolylacted filament yarns as disclosed in Patent Document 1, theimprovements of bulkiness, abrasion resistance and buckling resistancewere insufficient.

In the textured polylacted filament yarn obtained by the techniquedisclosed in Patent Document 2, the filament yarn properties, especiallythe filament yarn tenacity, was insufficient (In Patent Document 2, thefilament yarn tenacity was 1.6 cN/dtex in Example 1, 1.7 cN/dtex inExample 2, 1.5 cN/dtex in Example 3, 1.8 cN/dtex in Example 4, and 1.5cN/dtex in Example 5). Accordingly, in the carpet constituted by thetextured polyactic acid filament yarns, it was poor in abrasionresistance and buckling resistance, resulting in limited applications.

Furthermore, in the carpet constituted by the spun-dyed texturedpolyactic acid filament yarns disclosed in Patent Document 3, theimprovements of bulkiness, abrasion resistance and buckling resistancewere insufficient. For example, in the case of constituting anautomobile option carpet, an automobile line matt, a tile carpet, or ahousehold roll carpet by the spun-dyed textured polyactic acid filamentyarns, the durability, such as, e.g., bulkiness, abrasion resistance andbuckling resistance, was not sufficiently satisfied at practical level.Patent Document 3 is completely silent about a hot water shrinkageratio, etc., related to the orientation/crystal of the texturedpolylacted filament yarn.

Patent Document 4 is directed to a biodegradable carpet in which along-filament yarn nonwoven fabric made of polylactic acid seriespolymer is used as the base fabric, polylactic acid polymer is used asthe pile yarn, and biodegradable material is used for the backingmaterial. However, it is silent about durability, such as abrasionresistance or bulkiness, of the carpet manufactured by using polylacticacid series polymer.

Patent Document 5 refers to a biodegradable carpet using fatty acidpolyester, especially polylactic acid. Although Patent Document 5 refersto the covering property and the firm-elastic feeling of the carpetproduced using polylacted resin filament yarns, it is silent about thedurability, such as, e.g., the abrasion resistance or bucklingresistance, of the carpet.

Patent Document 6 refers to a carpet using filament yarns and adhesivemade of polylactic acid resin, especially a biodegradable carpet.However, it is completely silent about the durability, such as, e.g.,abrasion resistance or buckling resistance, of the carpet manufacturedby using polylactic acid series polymer.

The aforementioned Patent Documents 4 to 6 do not refer to durability,such as, e.g., abrasion resistance or buckling resistance, of a carpet.Therefore, it can be hardly said that a carpet obtained by the techniquehas reached a satisfactory level in durability, such as, e.g., abrasionresistance, bulkiness and buckling resistance.

The present invention was made in view of the aforementioned technicalbackground, and aims to provide a spun-dyed textured polylacted filamentyarn excellent in bulkiness, toughness and abrasion resistance and theproduction method thereof. It also aims to provide a carpet using thetextured filament yarns and having sufficient voluminous look andtexture which is excellent in bulkiness, abrasion resistance andbuckling resistance.

In order to attain the aforementioned object of the invention, thepresent inventors eagerly studied to improve deficiency of filament yarnproperties, deficiency of crimping characteristics, nonconformance ofhydrothermal contraction characteristics, insufficient abrasionresistance or insufficient bulkiness of a carpet due to the above. As aresult, the inventors found the fact that the aforementioned problemscan be solved by limiting the cross-sectional configuration of thefilament constituting the spun-dyed textured filament yarn to a specificconfiguration, by limiting the relative viscosity to a specified rangeand by limiting the tenacity, the elongation, the total fineness, thefilament fineness, the hot water shrinkage ratio and the dry heat crimpratio to the respective specified range, and completed the presentinvention. That is, the present invention provides the following means.

[1] A spun-dyed textured polylacted filament yarn, comprising a texturedpolylacted filament yarn,

wherein the textured polylacted filament yarn comprises a filamenthaving an approximately circular or circular cross-section and has arelative viscosity of 2.5 to 3.8,

wherein the textured polylacted filament yarn contains a coloring agentin an amount of 0.01 to 3 mass %, and

wherein the textured polylacted filament yarn is 1.75 to 3.5 cN/dtex intenacity, 35 to 60% in elongation, 500 to 3,500 dtex in total fineness,2.5 to 25 dtex in a filament fineness, 2 to 8% in hot water shrinkageratio, and 5 to 25% in dry heat crimp ratio.

[2] The spun-dyed textured polylacted filament yarn as recited in theaforementioned Item 1, wherein the filament has an approximatelycircular or circular cross-section having a degree of deformation lessthan 1.5.

[3] The spun-dyed textured polylacted filament yarn as recited in theaforementioned Item 1 or 2, wherein the coloring agent is at least onepigment selected from the group consisting of an inorganic pigment andan organic pigment.

[4] A carpet in which the spun-dyed textured polylacted filament yarn asrecited in any one of the aforementioned Items 1 to 3 is used as atleast a part of constituent yarn.

[5] A method for manufacturing a spun-dyed textured polylacted filamentyarn, comprising the steps of:

spinning a polylacted resin composition containing a coloring agent anda polylacted resin and having a coloring agent content of 0.01 to 3 mass% and a relative viscosity of 2.5 to 3.8 to obtain spun filamentscomprising a filament having an approximately circular or circularcross-section and a degree of deformation less than 1.5;

drawing the spun filaments at a draw ratio of 3 times to 6 times with adraw roller set to 70 to 125° C.;

heat-setting the drawn spun filaments with a heat-set roller set to 100to 150° C.;

giving crimps to the heat-set drawn spun filaments by bringing a heatedfluid of 90 to 160° C. into contact with the heat-set drawn spunfilaments using a texturing device; and

cooling the textured spun filaments after the crimping step to atemperature lower than a glass transition temperature of polylactedpolymer.

[6] A method for manufacturing a spun-dyed textured polylacted filamentyarn, comprising the steps of:

obtaining spun filaments by extruding a polylacted resin compositioncontaining a coloring agent and a polylacted resin and having a coloringagent content of 0.01 to 3 mass % and a relative viscosity of 2.5 to 3.8through a spinning nozzle into filaments each having an approximatelycircular or circular cross-section and a degree of deformation less than1.5, cooling the filaments with quench air, and then coating thefilaments with lubricant;

drawing the spun filaments at a draw ratio of 3 times to 6 times with adraw roller set to 70 to 125° C.;

heat-setting the drawn spun filaments with a heat-set roller set to 100to 150° C.;

giving crimps to the heat-set drawn spun filaments by bringing a heatedfluid of 90 to 160° C. into contact with the heat-set drawn spunfilaments using a texturing device; and

cooling the textured spun filaments after the crimping step to atemperature lower than a glass transition temperature of the polylactedpolymer.

[7] The method of manufacturing a spun-dyed textured polylacted filamentyarn as recited in the aforementioned Item 5 or 6, wherein the followingrelational expression is met:

30° C.≧S−R≧−10° C.

where “S” is a temperature of the heat-set roller, and “R” is atemperature of the heated fluid in the texturing device.

[8] The method of manufacturing a spun-dyed textured polylacted filamentyarn as recited in any one of the aforementioned Items 5 to 7, whereinthe drawn spun filaments are heat-set with a heat-set roller set to atemperature range of 100° C. to a softening point of the polylactedpolymer.

[9] The method of manufacturing a spun-dyed textured polylacted filamentyarn as recited in any one of the aforementioned Items 5 to 8, whereincrimps are given to the heat-set drawn spun filaments by bringing theheated fluid set to a temperature range of 90° C. to a softening pointof the polylacted polymer into contact with the filaments using thetexturing device.

[10] The method of manufacturing a spun-dyed textured polylactedfilament yarn as recited in any one of the aforementioned Items 5 to 9,further comprising a step of subjecting the textured spun filaments wentthrough the cooling step to an entangle process using a entangleprocessing device.

[11] A spun-dyed textured polylacted filament yarn manufactured by themanufacturing method as recited in any one of the aforementioned Items 5to 10.

[12] A carpet in which at least a part of constituent yarns of thecarpet is constituted by the spun-dyed textured polylacted filament yarnas recited in the aforementioned Item 11.

[13] A carpet using a spun-dyed textured polylacted filament yarncomprising a filament having an approximately circular or circularcross-section as a pile yarn.

[14] The carpet as recited in the aforementioned Item 13, wherein thespun-dyed textured polylacted filament yarn meets all of the followingcharacteristics (1) to (7):

(1) a filament has an approximately circular or circular cross-sectionhaving a degree of deformation less than 1.5, wherein the degree ofdeformation is expressed by a ratio (B/A) of a diameter B of ancircumscribed circle of the filament cross-section to a diameter A of ainscribed circle of the filament cross-section;

(2) relative viscosity (RV) is 2.5 to 3.8;

(3) tenacity is 1.75 to 3.5 cN/dtex;

(4) elongation is 35 to 60%;

(5) a filament fineness is 2.5 to 25 dtex;

(6) hot water shrinkage ratio is 2 to 8%; and

(7) dry heat crimp ratio is 5 to 25%.

[15] The carpet as recited in the aforementioned Item 13 or 14, whereinthe pile yarn comprises a single yarn and/or two or more doubled andtwisted yarns made of a non-twisted and/or twisted spun-dyed texturedpolylacted filament yarn.

[16] The carpet as recited in any one of the aforementioned Items 13 to15, wherein an average length of piles forming a carpet is 5 to 15 mm,and a weight per unit area of the piles is 500 to 3,000 g/m².

[17] The carpet as recited in any one of the aforementioned Items 13 to16, wherein an abrasion amount of pile yarns forming a carpet measuredby a TABER abrasion test (abrasion ring: H-18, abrasion number: 2,500times) is 5 to 30 mass %.

[18] A carpet comprising a spun-dyed textured polylacted filament yarnand a spun-dyed textured synthetic filament yarn as a pile yarn, whereinan abrasion amount of the pile yarn forming a carpet measured by a TABERabrasion test (abrasion ring: H-18, abrasion number: 5,000 times) is 5to 30 mass %.

[19] The carpet as recited in the aforementioned Item 18, wherein thespun-dyed textured synthetic filament yarn is at least one of spun-dyedtextured synthetic filament yarn selected from the group consisting of aspun-dyed textured polyester filament yarn, a spun-dyed textured nylonfilament yarn, and a spun-dyed textured polypropylene filament yarn.

[20] The carpet as recited in the aforementioned Item 18 or 19, whereinthe spun-dyed textured polylacted filament yarn meets all of thefollowing characteristics (1) to (7):

(1) a filament has an approximately circular or circular cross-sectionhaving a degree of deformation less than 1.5, wherein the degree ofdeformation is expressed by a ratio (B/A) of a diameter B of ancircumscribed circle of the filament cross-section to a diameter A of ainscribed circle of the filament cross-section;

(2) relative viscosity (RV) is 2.5 to 3.8;

(3) tenacity is 1.75 to 3.5 cN/dtex;

(4) elongation is 35 to 60%;

(5) a filament fineness is 2.5 to 25 dtex;

(6) hot water shrinkage ratio is 2 to 8%; and

(7) dry heat crimp ratio is 5 to 25%.

[21] The carpet as recited in any one of the aforementioned Items 18 to20, wherein an average length of piles forming a carpet is 5 to 15 mm,and a weight per unit area of the piles is 500 to 3,500 g/m².

[22] The carpet as recited in any one of the aforementioned Items 18 to21, wherein the spun-dyed textured polylacted filament yarn is made ofplant-derived material, and the spun-dryed textured synthetic filamentyarn is made of petroleum-derived material.

EFFECTS OF THE INVENTION

In the invention [1], the cross-section of the filament constituting thespun-dyed textured filament yarn is limited to a specific configuration,the relative viscosity is limited so as to fall within a specific range,and the tenacity, the elongation, the total fineness, the filamentfineness, the hot water shrinkage ratio and the dry heat crimp ratio areeach limited so as to fall within respective specified ranges.Therefore, a spun-dyed textured polylacted filament yarn excellent inbulkiness, toughness, and abrasion resistance can be provided.

In the invention [2], since the filament has an approximately circularor circular cross-section having a degree of deformation less than 1.5,the abrasion resistance can be further improved.

In the invention [3], since as the coloring agent, at least one pigmentselected from the group consisting of an inorganic pigment and anorganic pigment is used, there is an advantage that the heat resistance,the light resistance, the weather resistance can be improved as comparedwith other coloring agents such as colorants (in other words, in thecase of colorants, since they can be easily decomposed, sufficient heatresistance cannot be obtained).

In the invention [4], since the spun-dyed textured polylacted filamentyarn as recited in any one of the aforementioned Items [1] to [3] isused as at least a part of constituent yarns, the carpet is rich involuminous look, and rich in texture and excellent in bulkiness,abrasion resistance and buckling resistance.

In the invention [5], a spun-dyed textured polylacted filament yarnexcellent in bulkiness, toughness and abrasion resistance can bemanufactured. Furthermore, since spun-dyed polylacted polymer is used asfilament yarn forming material, a dyeing process requiring a heattreatment as a post-process can be eliminated. Therefore, there is anadvantage that adverse effects (e.g., deterioration of mechanicaltenacity) due to the heat treatment can be avoided.

In the invention [6], a spun-dyed textured polylacted filament yarnexcellent in bulkiness, toughness, and abrasion resistance can bemanufactured. Furthermore, since spun-dyed polylacted polymer is used asfilament yarn forming material, dyeing process requiring a heattreatment as a post-process can be eliminated. Therefore, there is anadvantage that adverse effects (e.g., deterioration of mechanicaltenacity) due to the heat treatment can be avoided. Since a spunfilament is obtained by extruding a polylacted resin composition througha spinning nozzle, cooling the filament with quench air, and thencoating the filament with lubricant, a spun filament can be manufacturedefficiently, and smoothness and antistatic property can be given to thespun filament by the coating of the lubricant. Furthermore, since thetextured filament yarn is cooled to a temperature lower than the glasstransition temperature of the polylacted polymer, a spun-dyed texturedpolylacted filament yarn to which sufficient crimp is given can bemanufactured.

In the invention [7], a spun-dyed textured polylacted filament yarn ismanufactured under the conditions meeting the following relationalexpression:

30° C.≧S−R≧−10° C.

where “S” is a temperature of the heat-set roller, and “R” is atemperature of the heated fluid in the texturing device. Therefore, boththe tenacity and the elongation of the spun-dyed textured polylactedfilament yarn to be obtained can be improved.

In the invention [8], the drawn spun filament is heat-set with aheat-set roller set to a temperature ranging from 100° C. to atemperature of a softening point of the polylacted polymer. Therefore,appropriate polylacted polymer crystallization can be attained,resulting in improved tenacity and elongation of the textured filamentyarn.

In the invention [9], crimps are given to the heat-set drawn filamentyarn by bringing the heated fluid having a temperature ranging from 90°C. to a temperature of a softening point of the polylacted polymer intocontact with the filament yarn using a texturing device. Therefore,damages to the orientated crystallized filament yarn can be reduced atthe time of giving crimp, resulting in improved tenacity and elongationof the spun-dyed textured polylacted filament yarn.

In the invention [10], the textured filament yarn went through thecooling step is subjected to an entangle process using a entangleprocessing device. Therefore, the tufting property of the texturedfilament yarn at the time of the tufting can be improved.

In the invention [11], a spun-dyed textured polylacted filament yarnexcellent in loftiness, toughness and abrasion resistance can beprovided.

In the invention [12], a carpet sufficient in voluminous look, rich intexture, excellent in loftiness, abrasion resistance and bucklingresistance can be provided.

In the invention [13], since the filament constituting the spun-dyedtextured polylacted filament yarn is approximately circular or circularin cross-section, a carpet excellent in abrasion resistance can beprovided. Furthermore, using a spun-dyed textured polylacted filamentyarn can eliminate a dyeing process requiring a heat treatment in theproduction steps of a carpet, which can avoid adverse effects (e.g.,deterioration of mechanical tenacity) due to the heat treatment. Thus, acarpet improved in plant-derived ratio and excellent in toughness andabrasion resistance can be provided.

In the invention [14], the cross-section and the degree for deformationof the filament constituting the spun-dyed textured polylacted filamentyarn are each specifically limited, the relative viscosity is limited soas to fall within a specific range, and the tenacity, the elongation,the filament fineness, the hot water shrinkage ratio, and the dry heatcrimp ratio are limited so as to fall within respective specifiedranges. Thus, a carpet improved in plant-derived ratio and excellent inloftiness, toughness and abrasion resistance can be provided.

In the invention [15], the pile yarn comprises a single and/or two ormore doubled and twisted yarns made of a non-twisted and/or twistedspun-dyed textured polylacted filament yarn. Therefore, in accordancewith the requirements of texture of the carpet pile portion, variousyarns can be employed.

In the invention [16], since an average length of piles forming a carpetusing pile yarns made of a spun-dyed textured polylacted filament yarnis 5 to 15 mm, and a weight per unit area of the piles is 500 to 3,000g/m², a carpet excellent in loftiness and abrasion resistance and havingno bottom-out feeling can be provided.

In the invention [17], since an abrasion amount of pile yarns forming acarpet measured by a TABER abrasion test (abrasion ring: H-18, abrasionnumber: 2,500 times) is 5 to 30 mass %, a carpet excellent in abrasionresistance can be provided.

In the invention [18], since a spun-dyed textured polylacted filamentyarn and a spun-dyed textured synthetic filament yarn are used as pileyarns, a carpet having abrasion resistance superior to a carpet made ofonly spun-dyed textured polylacted filament yarns can be provided.Furthermore, since the abrasion amount of the pile yarn forming a carpetmeasured by a TABER abrasion test (abrasion ring: H-18, abrasion number:5,000 times) is 5 to 30 mass %, a carpet excellent in abrasionresistance can be provided. Furthermore, because of using a spun-dyedpolylacted filament yarn, a dyeing process requiring a heat treatment asa post-process can be eliminated at the time of manufacturing a carpet.Therefore, adverse effects (e.g., deterioration of mechanical tenacity)due to the heat treatment can be avoided, and a carpet excellent intoughness and abrasion resistance can be provided.

In the invention [19], at least one of spun-dyed textured syntheticresin filament yarns selected from the group consisting of a spun-dyedtextured polyester filament yarn, a spun-dyed textured nylon filamentyarn, and a spun-dyed textured polypropylene filament yarn and aspun-dyed textured synthetic filament yarn are used as pile yarns.Therefore, a dyeing process requiring a heat treatment can be eliminatedat the time of manufacturing a carpet and combustion heat can be reducedduring the burning, resulting in easy incinerating.

In the invention [20], since the cross-section and the degree ofdeformation of the filament constituting the spun-dyed texturedpolylacted filament yarn are each specifically limited, the relativeviscosity is limited so as to fall within a specific range, and thetenacity, the elongation, the filament fineness, the hot water shrinkageratio, and the dry heat crimp ratio are limited so as to fall withinrespective specified ranges, by using the spun-dyed textured polylactedfilament yarn together with the spun-dyed textured synthetic filamentyarn, a carpet further improved in loftiness, toughness and abrasionresistance can be provided.

In the invention [21], since the average length of piles forming acarpet is 5 to 15 mm and the weight per unit area of the piles is 500 to3,500 g/m², a carpet excellent in loftiness and abrasion resistance andhaving no bottom-out feeling can be provided.

In the invention [22], a carpet using plant-derived materials excellentin toughness and abrasion resistance can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural view showing an example of amanufacturing method for use in manufacturing a spun-dyed polylactedfilament yarn.

FIG. 2 is an explanatory view for explaining a degree of deformation ofa filament.

FIG. 3 is a schematic view showing an example of a carpet according tothe third invention.

FIG. 4 is a schematic view showing an example of a carpet according tothe third invention.

DESCRIPTION OF THE REFERENCE NUMERALS

-   -   2 . . . preheating roller    -   3 . . . draw roller    -   4 . . . heat-set roller    -   5 . . . texturing device    -   6 . . . textured filament yarn    -   20 . . . cooling drum    -   21 . . . entangle processing device

BEST MODE FOR CARRYING OUT THE INVENTION

A spun-dyed textured polylacted filament yarn according to the firstinvention is comprised of a filament having an approximately circular orcircular cross-section. This textured filament yarn is 2.5 to 3.8 inrelative viscosity. Furthermore, the spun-dyed textured polylactedfilament yarn according to the first invention is made from a polylactedresin compound containing a coloring agent and polylacted resin.

The polylacted resin constituting the polylacted resin compound to beused as the raw material of the spun-dyed textured polylacted filamentyarn is polylacted resin in which lactide monomer containing L-lactideas a main ingredient is polymerized. It is preferable that thepolylacted resin contains L-lactide in the amount of 90 mass % or morein the lactide monomer. In other words, D-lactide can be contained inthe lactide monomer within a range not exceeding 10 mass %. If theoptical purity (optical purity of L-lactide) of the lactide monomer tobe used is 90% or more, the polylacted polymer becomes crystalline,which is preferable. If the optical purity (optical purity of L-lactide)of the lactide monomer to be used is 97% or more, the melting pointbecomes about 170° C., which is more preferable. It should be noted thatpolylacted polymer in which a component other than lactide iscopolymerized can be used so long as the amount of the component fallswithin the range which does not harm the effects of the presentinvention. In the case of copolymerizing components other than lactide,the lactide unit should be 70 mass % or more but less than 100 mass % ofthe repeating unit of the polymer molecular chain, preferably 80 mass %or more but less than 100 mass %, more preferably 90 mass % or more butless than 100 mass %.

The relative viscosity (RV) of the spun-dyed textured polylactedfilament yarn of the first invention is required to be 2.5 to 3.8. Therelative viscosity is a value measured as a mixed solution of 20° C.,phenol/tetrachloroethane=60/40 (mass ratio). If the relative viscosityis less than 2.5, sufficient tenacity and elongation cannot be given tothe polylacted textured filament yarn, and abrasion property appropriateto the carpet usage cannot be given thereto. On the other hand, if therelative viscosity exceeds 3.8, the melt viscosity becomes highexcessively. As a result, it is required to raise the spinningtemperature, resulting in decreased relative viscosity of the texturedpolylacted filament yarn which is extremely lower than a before-meltlevel thereof and also resulting in insufficiently improved tenacity. Inaddition, this also causes difficulty in spinning. It is more preferablethat the relative viscosity of the spun-dyed textured polylactedfilament yarn is 2.8 to 3.6.

Furthermore, the polylacted resin compound used as a material of thespun-dyed textured polylacted filament yarn of the first inventioncontains a coloring agent in the amount of 0.01 to 3 mass %. Thisconcentration can give an appropriate color density to the texturedfilament yarn, resulting in improved design property. If theconcentration is set to 0.01 mass % or more, generation of color shadingdue to the coloring agent irregularity can be prevented. If it is set to3 mass % or less, generation of filament yarn breakage can besufficiently prevented. It is especially preferable that the ratio ofcontent of the coloring agent is 0.05 to 1 mass %. Furthermore, thecoloring agent can be used together with a dispersing agent normallyused (e.g., olefin series compound).

In addition to polymer (including polymer particles) other thanpolylacted polymer, it should be noted that any additive agent, such as,e.g., a delustering agent, a plasticizing agent, a fire retardant, anantistatic agent, an odor eliminating agent, an antibacterial agent, anantioxidant agent, a heat resisting agent, a light resistant agent, andan ultraviolet [UV] absorber, can be added to the polylacted resincomposition so long as the amount falls within the range which does notharm the effects of the present invention.

The spun-dyed textured polylacted filament yarn of the first inventionhas a filament having an approximately circular or circularcross-section (i.e., filament is circular in cross-section). Thiscross-sectional configuration gives abrasion resistance to the filamentyarn. That is, a filament yarn can have resistance to abrasion. Amongother things, it is preferable that the cross-sectional configuration ofthe filament is an approximately circular or circular having a degree ofdeformation less than 1.5 (exceeding 1 but less than 1.5). If the degreeof deformation exceeds 1.5, the covering property of the texturedpolylacted filament yarn can be improved. However, due to the largedegree of deformation, the hard and brittle properties inherent in thepolylacted polymer tend to be exerted, resulting in deterioratedabrasion resistance of the filament yarn, and therefore it is notpreferable. The degree of deformation is expressed by a ratio (B/A) of adiameter B of an circumscribed circle of the filament cross-section to adiameter A of a inscribed circle of the filament cross-section (see FIG.2).

Furthermore, the spun-dyed textured polylacted filament yarn of thefirst invention meets all of the following characteristics (1) to (6):

(1) tenacity is 1.75 to 3.5 cN/dtex;

(2) elongation is 35 to 60%;

(3) total fineness is 500 to 3,500 dtex;

(4) a filament fineness is 2.5 to 25 dtex;

(5) hot water shrinkage ratio is 2 to 8%; and

(6) dry heat crimp ratio is 5 to 25%.

The tenacity of the spun-dyed textured polylacted filament yarn is 1.75to 3.5 cN/dtex. If the tenacity of the textured filament yarn is lessthan 1.75 cN/dtex, when the textured filament yarn is used as a carpet,a part of the textured filament yarn may sometimes be worn out, whichcannot give sufficient abrasion resistance appropriate to a carpet. Itis preferable that the tenacity of the spun-dyed textured polylactedfilament yarn is 2.0 to 3.25 cN/dtex, more preferably 2.25 to 3.25cN/dtex.

The elongation of the spun-dyed textured polylacted filament yarn is 35to 60%. If the elongation of the textured filament yarn is less than35%, when the textured filament yarn is used as a carpet, a part of thetextured filament yarn may sometimes be worn out, which cannot givesufficient abrasion resistance appropriate to a carpet. It is preferablethat the elongation of the spun-dyed textured polylacted filament yarnis 40 to 55%.

If the tenacity of the spun-dyed textured polylacted filament yarn is2.0 to 3.25 cN/dtex and the elongation of the spun-dyed texturedpolylacted filament yarn is 40 to 55%, the filament yarn can have highertoughness, which is preferable. However, raising of the tenacitygenerally causes deterioration of elongation. Even if the elongation isset to 35% or more, the tenacity is merely increased to 3.5 cN/dtex.Furthermore, if the elongation exceeds 60%, the tenacity cannot beincreased to 1.75 cN/dtex or more.

Furthermore, the total fineness of the spun-dyed textured polylactedfilament yarn falls within the range of 500 to 3,500 dtex. Setting thetotal fineness within this range can provide a spun-dyed texturedpolylacted filament yarn preferably used for a carpet such as a tuftedcarpet, but not limited thereto. It is preferable that the totalfineness of the spun-dyed textured polylacted filament yarn falls withinthe rage of 1,000 to 3,000 dtex.

The filament fineness of the spun-dyed textured polylacted filament yarnfalls within the range of 2.5 to 25 dtex. If the filament fineness isless than 2.5 dtex, it becomes difficult to perform the yarn-makingstably. If the filament fineness exceeds 25 dtex, it become difficult toobtain the filament yarn property of the spun-dyed textured polylactedfilament yarn of the present invention and the hard and brittleproperties inherent in the polylacted polymer tend to be exerted,resulting in deteriorated abrasion resistance of the filament yarn, andtherefore it is not preferable. This tendency becomes prominent as thedegree of deformation of the cross-section of the polylacted filamentincreases in the same filament fineness. Accordingly, the smaller degreeof deformation of the filament is preferable. It is preferable that thefilament fineness of the spun-dyed textured polylacted filament yarnfalls within the range of 4 to 20 dtex, more preferably 5 to 15 dtex. Incases where the filament fineness falls within the range of 2.5 to 25dtex, the soft and brittle property of the polylacted polymer can beweakened and the tenacity and the elongation of the spun-dyed texturedpolylacted filament yarn can be further improved and that the abrasionresistance of a carpet using the spun-dyed textured polylacted filamentyarn can also be improved.

The hot water shrinkage ratio of the spun-dyed textured polylactedfilament yarn falls within the range of 2 to 8%. If the hot watershrinkage ratio is less than 2%, the crystallinity of the spun-dyedtextured polylacted filament yarn becomes higher. As a result, the hardand brittle property of the polylacted polymer will be easily exerted,resulting in poor balanced tenacity and elongation and insufficientabrasion resistance as a carpet. On the other hand, if the hot watershrinkage ratio exceeds 8%, there are problems that filament yarnshrinkage occurs at the time of the heat-set treatment and it becomesdifficult to administrate each carpet manufacturing step. Among otherthings, it is preferable that the hot water shrinkage ratio of thespun-dyed textured polylacted filament yarn falls within the range of 3to 6%.

The dry heat crimp ratio of the spun-dyed textured polylacted filamentyarn falls within the range of 5 to 25%. This dry heat crimp ratio is aparameter showing the loftiness of the spun-dyed textured polylactedfilament yarn, and a value showing the degree of crimps formed bytreating the spun-dyed textured polylacted filament yarn with heated airof 100° C. If the dry heat crimp ratio is less than 5%, crimping becomesinsufficient, the loftiness as a carpet becomes insufficient, and thebuckling resistance becomes poor. On the other hand, it is difficult toobtain a textured polylacted filament yarn having a dry heat crimp ratioexceeding 25% by currently available manufacturing technique. Even if itis possible, the carpet using the textured filament yarn becomes afelt-like carpet. Among other things, the dry heat crimp ratiopreferably falls within the range of 8 to 20%.

As the coloring agent, for example, an inorganic pigment and an organicpigment can be exemplified. But the coloring agent is not specificallylimited thereto so long as it gives a color to the textured filamentyarn. Examples of the inorganic pigment include oxides such as, e.g.,titanium oxide, zinc oxide, titan yellow, zinc-iron series brown,titan-cobalt series green, cobalt green, cobalt blue, and cupper-ironseries brown, ferrocyanide such as, e.g., iron blue, silicate such as,e.g., ultramarine blue pigment, carbonate such as, e.g., calciumcarbonate, phosphate such as, e.g., manganese violet, carbon black,aluminum powder, bronze powder, titanium powder covering mica. Examplesof the organic pigment include phthalocyanine series such as, e.g.,cupper phthalocyanine blue, cupper phthalocyanine green, and brominatedcupper phthalocyanine green, perylene series such as, e.g., perylenescarlet, perylene rare, and isoindolinon series.

Among other things, it is preferable to use at least one type of pigmentselected from the group consisting of inorganic pigment and organicpigment. It is more preferable to use at least one type of pigmentselected from the group consisting of carbon black, oxide seriesinorganic pigment, ferrocyanide series inorganic pigment, silicateseries inorganic pigment, carbonate series inorganic pigment, phosphateseries inorganic pigment, phthalocyanine series organic pigment,perylene series organic pigment and isoindolinon series organic pigment.

Next, the method for manufacturing the spun-dyed textured polylactedfilament yarn having the aforementioned features will be explained.

Initially, a polylacted polymer is spun to obtain a spun filament(spinning process). For example, as shown in FIG. 1, polylacted resin ispoured in through the polylacted resin inlet 10 and a coloring agent(pigment, etc.) is poured in through the coloring agent inlet 11. Aftermelt-blending them in the extruder 12 having vents 13, they are extrudedthrough the spinning nozzle 15 attached to the spinning head 14 to formfilaments. At this time, the configuration of the hole of the spinningnozzle 15 should be appropriately designed so that the filament to beobtained has an approximately circular or circular cross-section havingthe degree of deformation of the cross-section of the filament less than1.5. The mixing amount of the coloring agent is adjusted so that thecoloring agent content rate falls within the range of 0.01 to 3 mass %.It is preferable that the melt-blending temperature in the extruder 12is set to 210 to 235° C. As the polylacted resin, polylacted resinhaving relative viscosity of 2.8 to 3.8, more preferably 3.0 to 3.6, isused. The relative viscosity is a value measured as a mixed solution of20° C., phenol/tetrachloroethane=60/40 (mass ratio). The reasons forusing the polylacted resin having relative viscosity of 2.8 to 3.8 arethe same reasons as mentioned above. As the coloring agent, a coloringagent in the form of a master batch in which a coloring agent ispreviously added to polylacted polymer can be used.

The polylacted resin is generally 0.4 to 0.5 mass % (4,000 to 5,000 ppm)in official moisture regain in the polymer. In order to use polylactedpolymer for melt-spinning, it is preferable that the official moistureregain in the polylacted resin is 0.01 mass % (100 ppm) or less, morepreferably 0.005 mass % (50 ppm) or less. For example, the water contentin the polylacted resin is decreased by drying the polylacted resin at atemperature of 100 to 130° C. for about 5 hours using a vacuum hot airdrying machine. In the case of using a biaxial extruder with vents, itis practically possible to use undried polylacted resin, andmelt-spinning can be performed while maintaining the relative viscosityof the polylacted polymer.

The configuration and the size of the hole of the spinning nozzle 15 aredesigned so that a desired spun-dyed textured polylacted filament yarncan be obtained considering the melt viscosity, the spinningtemperature, the quenching conditions after the spinning.

Subsequently, the filaments extruded from the spinning 15 are cooledwith quench air from the quench air blowing apparatus 16 (see FIG. 1).

Thereafter, after applying lubricant to the filaments with the lubricantapplying apparatus 17, a spun filament yarn is obtained by bundlingthem. The lubricant is not specifically limited, but can be, forexample, the lubricant having lubricating agent as a main gradient andcontaining, e.g., an emulsifying agent and an antistatic agent. Thepreferable lubricant composition is exemplified as follows. As thelubricating agent, it is preferable to use neopentyl glycol dioleate. Asthe emulsifying agent, it is preferable to use polyoxyethylene castoroil or polyoxyalkylene sorbitan ester. As the antistatic agent, it ispreferable to use polyoxyethylene alkyl phosphate. Furthermore,depending on the needs, additive agents such as, e.g., an antioxidizingagent and an ultraviolet [UV] absorber can be added to the lubricant.The preferable content rate of each composition of the lubricant is asfollows: the lubricating agent is 35 to 75 mass %; the emulsifying agentis 20 to 60 mass %; and the antistatic agent is 0.5 to 8 mass %.

By applying the lubricant, the tenacity and the elongation of thetextured filament yarn can be stably secured at the spinning andexpanding steps for manufacturing a spun-dyed textured polylactedfilament yarn and generation of crimps at the crimping step can bestably secured. Furthermore, electrostatic generation of the carpetusing the spun-dyed textured polylacted filament yarn can be suppressed,and the friction coefficient of the filament yarn surface can bereduced, which can further improve the abrasion resistance of the carpetsurface.

Thereafter, the spun filaments are received by the receiving roller 1rotating at a predetermined rotational rate. The rotational rate of thereceiving roller 1 is preferably set to 400 to 1,000 m/min. If therotational rate is less than 400 m/min., the filament yarn tensile forceduring the spinning becomes too low, which is not preferable. On theother hand, if it exceeds 1,000 m/min., the drawing speed and thecrimping process become higher. Therefore it is difficult to execute themanufacturing by a currently available practical process.

The spun filaments received by the receiving roller 1 are heat-drawn ata single stage or multiple stages using rollers 2, 3 and 4. In detail,initially, the received spun filaments are introduced to the preheatingroller 2 to preheat the spun filaments. At this time, it is preferableto set the temperature of the preheating roller 2 so that thetemperature falls within the range of 55 to 95° C. Setting thetemperature within the aforementioned range enables even preheating.Among other things, the temperature of the preheating roller 2 is set soas to fall within the range of 55 to 70° C.

Thereafter, the spun filaments are introduced from the preheating roller2 to the draw roller 3. At this time, the temperature of the draw roller3 is set so as to fall within the range of 70 to 125° C. If thetemperature is lower than 70° C., uneven extension may easily occur, andit is difficult to attain sufficient extension, which in turn maysometimes cause filament yarn breakage. On the other hand, if it exceeds125° C., the filament yarn loosens during the processing. It ispreferable to set the temperature of the draw roller 3 so that thetemperature falls within the range of 85 to 125° C., more preferably 95to 120° C. In the aforementioned temperature ranges, the temperature ofthe draw roller 3 is set to a temperature higher than the temperature ofthe preheating roller 2.

The draw ratio is set to 3 to 6 times. If it is less than 3 times,sufficient tenacity cannot be attained. If it exceeds 6 times,feather-like things will be generated remarkably. Among other things,the draw ratio is preferable set to 3.5 to 5.0 times.

Setting the temperature of the draw roller 3 so as to fall within therange of 70 to 125° C. and setting the draw ratio to 3 to 6 times makesit possible to obtain high tenacity, high elongation, and high crimpproperty of the spun-dyed textured polylacted filament yarn of the firstinvention, which in turn can realize the improved loftiness andexcellent abrasion resistance required for a carpet using the texturedfilament yarn as the constituent yarn of the carpet.

Thereafter, the spun filaments are introduced from the draw roller 3 tothe heat-set roller 4 to execute heat-setting. At this time, thetemperature of the heat-set roller 4 is set so as to fall within therange of 100 to 150° C. By setting the temperature so as to fall withinthe range, appropriate crystallization as a polylacted filament yarn canbe exerted, resulting in improved tenacity and elongation of thetextured filament yarn. Among other things, the temperature of theheat-set roller 4 is set so as to fall within the range of 105 to 140°C., more preferably 110 to 130° C. The still more preferable range is110 to 125° C. The temperature of the heat-set roller 4 is preferablyset to a temperature higher than the temperature of the draw roller 3within the range of 100 to 150° C.

Especially, in order to attain the high tenacity, high elongation, andhigh crimping characteristics of the spun-dyed textured polylactedfilament yarn of the first invention, it is preferable that thetemperature of the heat-set roller 4 is set to a temperature not higherthan the temperature (Ts) of the softening point of the polylactedpolymer. That is, it is preferable that the temperature of the heat-setroller 4 is set to a temperature not lower than 100° C. but not higherthan the temperature (Ts) of the softening point of the polylactedpolymer. The temperature of the softening point of polylacted polymer isabout 130° C., and therefore it is preferable that the temperature ofthe heat-set roller is set to 100 to 130° C., more preferably 110 to130° C., still more preferably 110 to 125° C.

Next, the heat-set spun filaments are introduced to the texturing device5 to give crimps to the spun filaments to thereby give loftiness(crimping step). The texturing device 5 is a device for giving crimps tothe filament yarn by bringing a heated fluid to the filament yarn. Thetemperature of the texturing device 5 is set so as to fall within therange of 90 to 160° C. If the temperature is lower than 90° C.,sufficient crimps cannot be given. On the other hand, a temperatureexceeding 160° C. may sometimes cause fusion bonding of the filaments.

In this embodiment, the texturing device 5 is equipped with a heatedfluid spraying nozzle device configured to spray a heated high pressurefluid in a thread-like manner to entangle filaments to thereby form athree-dimensional crimp and a compression heat treatment deviceconfigured to execute a compression heat treatment of the texturedfilament yarn with a heated fluid. The compression heat treatment deviceis a circular device in which metal plates are arranged at constantgaps. The heated pressurized fluid is sucked outwards between the metalplates. Within the texturing device 5, the filament yarn is folded andaccumulated for a certain period of time for a heat treatment.

As the heated fluid used for the texturing device 5, superheated vaporand heated air can be exemplified. Among other things, it is preferableto use heated air. The temperature of the heated air is set so as tofall within the range of 90 to 160° C., preferably 100 to 140° C., morepreferably 105 to 125° C. The temperature of the heated fluid can be setto a temperature falling within the range of 90 to 160° C., andappropriate conditions can be selected depending on the pressure andflow amount of the heated fluid, and the fineness and the crimpingprocessing rate, etc., of the polylacted filament yarn to be subjectedto crimping processing.

Furthermore, in order to attain high tenacity, high elongation and highcrimping characteristics of the spun-dyed textured polylacted filamentyarn of the first invention, it is preferable that the temperature ofthe heated fluid is set to a crystallization temperature (Tc) of thepolylacted polymer or below. If the temperature of the heated fluid setto 90° C. or above but not higher than the crystallization temperature(Tc) of the polylacted polymer, damages to the filament yarn at the timeof giving crimps to the orientated crystallized polylacted filament yarncan be decreased, resulting in desired crimping characteristics. Sincethe crystallization temperature of the polylacted polymer is about 115to 120° C., the temperature of the heated fluid is preferably set to 90to 120° C. Among other things, it is more preferable that thetemperature of the heated fluid is set to 90 to 115° C.

It is more preferable that the following relational expression is met:

30° C.≧S−R≧−10° C.

where “S” is a temperature of the heat-set roller, and “R” is atemperature of the heated fluid in the texturing device. When the aboveconditions are met, both the tenacity and the elongation of thespun-dyed textured polylacted filament yarn to be obtained can beimproved. Among other things, it is still more preferable that thefollowing relational expression is met:

-   -   20° C.≧S−R≧−10° C., still yet more preferably

15° C.≧S−R≧−10° C.

The textured filament yarn 6 to which crimps are given with thetexturing device 5 is cooled with a cooling drum 20. In this embodiment,the textured filament yarn 6 fed on the cooling drum 20 is transferredwhile being absorbed and cooled with the apertures formed in the surfaceof the cooling drum 20. At this cooling step, it is preferable that thetextured filament yarn 6 is cooled to a temperature lower than the glasstransition temperature (Tg) (57 to 60° C.) of the polylacted polymer.This makes it possible to manufacture a spun-dyed textured polylactedfilament yarn having sufficient crimps which would not be loosen even ifa certain time has passed. Among other things, it is preferable to coolthe textured filament yarn 6 to 30 to 55° C.

Thereafter, the textured filament yarn is passed into the entangleprocessing device 21 to execute the entangle processing. It ispreferable that high pressure air of 0.2 to 0.5 MPa is sprayed onto thetraveling textured filament yarn from the confounding nozzle at anapproximately rectangular angle.

Next, the entangled textured filament yarn is rolled up onto a winder22. The winding tensile force at that time is preferably set to 0.10cN/dtex. Among other things, it is preferable that the winding tensileforce falls within the range of 0.02 to 0.07 cN/dtex, more preferably0.03 to 0.05 cN/dtex.

The spun-dyed textured polylacted filament yarn obtained as mentionedabove is excellent in loftiness, toughness and abrasion resistance.Therefore, it can be preferably used as a constituent yarn of a carpet.For example, the obtained spun-dyed textured polylacted filament yarn istufted in the base fabric to produce a carpet. The base fabric is notspecifically limited, but can be exemplified by a nonwoven fabric madeof polylacted filament yarns, as well as polyester nonwoven fabric andpolypropylene nonwoven fabric. Among other things, as the base fabric, anonwoven fabric made of polylacted filament yarns is preferably used. Inthis case, the entire tufted carpet will be decomposed bymicroorganisms, etc., when discarded after the usage, which sufficientlycontributes to global environment protections.

The spun-dyed textured polylacted filament yarn of the first embodimentis not specifically limited to the filament yarn manufactured by theaforementioned exemplified manufacturing method.

The spun-dyed textured polylacted filament yarn of the first inventioncan be used in the form of a twisted yarn or a non-twisted yarn, or canbe used in the form of a combined filament yarn in which a non-twistedyarn and other non-twisted yarn are entangled with an air entanglingfacility. Furthermore, the spun-dyed textured polylacted filament yarnof the first invention can be used as a constituent yarn of a carpet bytwisting together with other nylon textured filament yarns,polypropylene textured filament yarns and polyester textured filamentyarns.

Sufficiently considering an environment-responsive recycle, as otherconstituent materials (materials other than the spun-dyed texturedpolylacted filament yarn) of a carpet, it is preferable to use polyestersuch as, e.g., PET (polyethylene terephthalate).

Furthermore, after forming a twisted textured filament yarn (twistednumber is preferably 150 to 250 times/m) by executing upper twisting andlower twisting using two or three spun-dyed textured polylacted filamentyarns of the first invention, the twisted textured filament yarn issubjected to a heated air treatment of 100 to 125° C. and a steamtreatment of 90 to 115° C. in a vacuum equipment to execute the twistfixing. As a result, a textured filament yarn further improved inloftiness, abrasion resistance and buckling resistance can be obtained,which in turn can provide a high-grade carpet by tufting the texturedfilament yarn.

The spun-dyed textured polylacted filament yarn of the first inventionand the spun-dyed textured polylacted filament yarn obtained by themanufacturing method of the first invention can be preferably used as,for example, a constituent yarn of a carpet. The carpet produced usingthe spun-dyed textured polylacted filament yarn of the first inventionand the carpet produced using the spun-dyed textured polylacted filamentyarn obtained by the manufacturing method of the first invention canhave sufficient loftiness and sufficient voluminous look and can beexcellent in abrasion resistance and buckling resistance.

Next, a carpet according to the second invention will be explained. Thespun-dyed textured polylacted filament yarn made from plant-derivedmaterial according to the second invention is a textured filament yarnobtained by yarn-making a specific polylacted polymer and subjecting itto a crimping process and will be formed into a pile yarn specified infilament yarn properties. The carpet manufacturing method is notspecifically limited, and can be any method for manufacturing, forexample, a woven carpet, an embroider carpet, an adhesive carpet and aknitted carpet. The configuration of the pile is not specificallylimited, and can be in the form of a cut pile, a loop file, or acut-and-loop file.

The polylacted polymer constituting a polylacted resin composition as amaterial of the spun-dyed textured polylacted filament yarn ispolylacted polymer in which lactide monomer containing L-lactide as amain ingredient is polymerized. It is preferable that 90 mass % or moreof the lactide monomer is constituted by L-lactide. In other words,D-lactide can be contained in the lactide monomer in the range notexceeding 10 mass %. When the optical purity (optical purity ofL-lactide) of the lactide monomer to be used is 90% or more, thepolylacted polymer becomes crystalline, which is preferable. When theoptical purity of the lactide monomer to be used is 97% or more, themelting point becomes about 170° C., which is more preferable.Polylacted polymer in which components other than lactide arecopolymerized can be used so long as the amount falls within the rangewhich does not harm the effects of the present invention. In the case ofcopolymerizing components other than lactide, the lactide unit should be70 mass % or more but less than 100 mass % of the repeating unit of thepolymer molecular chain, preferably 80 mass % or more but less than 100mass %, more preferably 90 mass % or more but less than 100 mass %.

The relative viscosity (RV) of the spun-dyed textured polylactedfilament yarn is required to be 2.5 to 3.8. The relative viscosity is avalue measured using a mixed solution of 20° C.,phenol/tetrachloroethane=60/40 (mass ratio). If the relative viscosityis less than 2.5, sufficient tenacity and elongation cannot be given tothe polylacted textured filament yarn, and abrasion property appropriateto the carpet usage cannot be given thereto. On the other hand, if therelative viscosity exceeds 3.8, the melt viscosity becomes highexcessively. As a result, it is required to raise the spinningtemperature, resulting in decreased relative viscosity of the texturedpolylacted filament yarn which is extremely lower than a before-meltlevel thereof and also resulting in insufficiently improved tenacity. Inaddition, this also causes difficulty in spinning. It is more preferablethat the relative viscosity of the spun-dyed textured polylactedfilament yarn is 2.8 to 3.6.

Furthermore, the polylacted resin compound used as a material of thespun-dyed textured polylacted filament yarn contains a coloring agent inthe amount of 0.01 to 3 mass %. This concentration can give anappropriate color density to the textured filament yarn, resulting inimproved design property. If the concentration is set to 0.01 mass % ormore, generation of color shading due to the coloring agent irregularitycan be prevented. If it is set to 3 mass % or less, generation offilament yarn breakage can be sufficiently prevented. It is especiallypreferable that the ratio of content of the coloring agent is 0.05 to1.0 mass %. Furthermore, the coloring agent can be used together with adispersing agent normally used (e.g., olefin series compound).

In addition to polymer (including polymer particles) other thanpolylacted polymer, it should be noted that any additive agent, such as,e.g., a delustering agent, a plasticizing agent, a fire retardant, anantistatic agent, an odor eliminating agent, an antibacterial agent, anantioxidant agent, a heat resisting agent, a light resistant agent, andan ultraviolet [UV] absorber, can be added to the polylacted resincomposition so long as the amount falls within the range which does notharm the effects of the present invention.

The carpet of the second invention using the spun-dyed texturedpolylacted filament yarn as a pile yarn is a carpet in which thespun-dyed textured polylacted filament yarn used as the pile yarn meetsall of the following characteristics (1) to (7):

(1) a filament has an approximately circular or circular cross-section(i.e., circular cross-sectional filament yarn). This cross-sectionalconfiguration gives abrasion resistance to the filament yarn. It ispreferable that the cross-sectional configuration of the filament is anapproximately circular or circular having a degree of deformation lessthan 1.5, wherein the degree of deformation is expressed by a ratio(B/A) of a diameter B of an circumscribed circle of the filamentcross-section to a diameter A of a inscribed circle of the filamentcross-section (see FIG. 2). If the degree of deformation exceeds 1.5,the covering property of the textured polylacted filament yarn can beimproved. However, due to the large degree of deformation, the hard andbrittle properties inherent in the polylacted polymer tend to beexerted, resulting in deteriorated abrasion resistance of the filamentyarn, and therefore it is not preferable;

(2) relative viscosity (RV) is 2.5 to 3.8;

(3) tenacity is 1.75 to 3.5 cN/dtex;

(4) elongation is 35 to 60%;

(5) a filament fineness is 2.5 to 25 dtex;

(6) hot water shrinkage ratio is 2 to 8%; and

(7) dry heat crimp ratio is 5 to 25%.

The tenacity of the spun-dyed textured polylacted filament yarn is 1.75to 3.5 cN/dtex. If the tenacity of the textured filament yarn is lessthan 1.75 cN/dtex, when the textured filament yarn is used as a carpet,the abrasion resistance becomes insufficient, and a part of the texturedfilament yarn may sometimes be worn out. It is preferable that thetenacity of the spun-dyed textured polylacted filament yarn is 2.0 to3.25 cN/dtex, more preferably 2.25 to 3.25 cN/dtex. The elongation ofthe spun-dyed textured polylacted filament yarn is 35 to 60%. If theelongation of the textured filament yarn is less than 35%, when thetextured filament yarn is used as a carpet, the abrasion resistancebecomes insufficient, and a part of the textured filament yarn maysometimes be worn out. It is preferable that the elongation of thespun-dyed textured polylacted filament yarn is 40 to 55%.

If the tenacity of the spun-dyed textured polylacted filament yarn is2.0 to 3.25 cN/dtex and the elongation of the spun-dyed texturedpolylacted filament yarn is 40 to 55%, the filament yarn can have highertoughness, which is preferable. However, raising of the tenacitygenerally causes deterioration of elongation. Even if the elongation isset to 35% or more, the tenacity is merely 3.5 cN/dtex. Furthermore, ifthe elongation exceeds 60%, the tenacity cannot be increased so as toexceed 1.75 cN/dtex.

Furthermore, the total fineness of the spun-dyed textured polylactedfilament yarn preferably falls within the range of 500 to 3,500 dtex. Solong as it falls within the range, it becomes an optimal spun-dyedtextured filament yarn for a tufted carpet, but not limited to suchusage. Among other things, it is preferable that the total fineness ofthe spun-dyed textured polylacted filament yarn falls within the rangeof 1,000 to 3,000 dtex. The filament fineness of the spun-dyed texturedpolylacted filament yarn falls within the range of 2.5 to 25 dtex. Ifthe filament fineness is less than 2.5 dtex, it becomes difficult toperform the yarn-making stably, and the loftiness of the carpet formedusing the textured filament yarns becomes insufficient. If the filamentfineness exceeds 25 dtex, it become difficult to obtain the filamentyarn property of the spun-dyed textured polylacted filament yarn and thehard and brittle properties inherent in the polylacted polymer tend tobe exerted, resulting in deteriorated abrasion resistance of thefilament yarn. This tendency becomes prominent as the degree ofdeformation of the cross-section of the polylacted filament yarnincreases in the same filament fineness. Accordingly, the smaller degreeof deformation of the filament is preferable. It is preferable that thefilament fineness of the spun-dyed textured polylacted filament yarnfalls within the range of 4 to 20 dtex, more preferably 5 to 15 dtex. Incases where the filament fineness falls within the range of 2.5 to 25dtex, the soft and brittle property of the polylacted polymer can beweakened and the tenacity and the elongation of the spun-dyed texturedpolylacted filament yarn can be further improved and that the abrasionresistance of a carpet using the spun-dyed textured polylacted filamentyarn can also be improved.

The hot water shrinkage ratio of the spun-dyed textured polylactedfilament yarn falls within the range of 2 to 8%. If the hot watershrinkage ratio is less than 2%, the crystallinity of the spun-dyedtextured polylacted filament yarn becomes higher. As a result, the hardand brittle property of the polylacted polymer will be easily exerted,resulting in poor balanced tenacity and elongation and resulting ininsufficient abrasion resistance as a carpet. On the other hand, if thehot water shrinkage ratio exceeds 8%, there are problems that filamentyarn shrinkage occurs at the time of the heat-set treatment and itbecomes difficult to administrate each carpet manufacturing step. Amongother things, it is preferable that the hot water shrinkage ratio of thespun-dyed textured polylacted filament yarn falls within the range of 3to 6%.

The dry heat crimp ratio of the spun-dyed textured polylacted filamentyarn falls within the range of 5 to 25%. This dry heat crimp ratio is aparameter showing the loftiness of the spun-dyed textured polylactedfilament yarn, and a value showing the degree of crimps formed bytreating the spun-dyed textured polylacted filament yarn with heated airof 100° C. If the dry heat crimp ratio is less than 5%, crimping becomesinsufficient, the loftiness as a carpet becomes insufficient, and thebuckling resistance becomes poor. On the other hand, it is difficult toobtain a textured polylacted filament yarn having a dry heat crimp ratioexceeding 25% by currently available manufacturing technique. Even if itis possible, the carpet using the textured filament yarn becomes afelt-like carpet. Among other things, the dry heat crimp ratiopreferably falls within the range of 8 to 20%.

As the coloring agent for the spun-dyed textured polylacted filamentyarn, for example, an inorganic pigment and an organic pigment can beexemplified. But the coloring agent is not specifically limited theretoso long as it gives a color to the textured filament yarn. As thecoloring agent, for example, at least one of pigments selected from thegroup comprising a carbon black, an inorganic pigment such as, e.g., anoxidization series organic pigment, a ferrocyanide inorganic pigment, asilicate inorganic pigment, a carbonate inorganic pigment, and aphosphate inorganic pigment, a phthalocyanine series organic pigment, aperylene series organic pigment, and an isoindolinon series organicpigment is used.

Hereinafter, a concrete manufacturing method of the spun-dyed texturedpolylacted filament yarn required in the second invention will beexplained, but not limited thereto.

As the polylacted resin for use in manufacturing the spun-dyed texturedpolylacted filament yarn, polylacted resin having a relative viscosity(RV) of 2.5 to 3.8 measured as a mixed solution of 20° C.,phenol/tetrachloroethane=60/40 (mass ratio) is used. In the carpet usageof the second invention, since the tenacity and the elongation of thetextured filament yarn, the crimping characteristics and the abrasionresistance are required, polylacted polymer having a high molecularweight, i.e., polymer having the above-specified relative viscosity,will be required.

As the inorganic pigment and the organic pigment to be used as acoloring agent for the spun-dyed textured polylacted filament yarn, atleast one pigment selected from the above-specified compounds is used.After adding a coloring agent to the polylacted polymer, yarn-making canbe performed.

Polylacted polymer in which the aforementioned polylacted polymer andthe coloring agent are mixed at a certain ratio with a mixing device issupplied to a biaxial extruder 12 with vents 13 and molten and extrudedfrom the spinning nozzle 15 via a spinning pack.

The spun-dyed textured polylacted filament yarn comprises a filamenthaving an approximately circular or circular cross-sectionalconfiguration. The degree of deformation of the filament cross-sectionexpressed by a ratio (B/A) of a diameter B of an circumscribed circle ofthe filament cross-section to a diameter A of a inscribed circle of thefilament cross-section is preferably less than 1.5.

Next, the spun filaments are cooled and solidified with quench air ofthe cooling device 16.

After applying a lubricant to the cooled and solidified spun filaments,the filaments are received with the receiving roller 1 rotating at apredetermined rotational rate.

The rotational speed of the receiving roller 1 is 400 to 1,000 m/mim.

The manufacturing method of the textured filament yarn according to thesecond invention is characterized in a direct spinning extension andcrimping process, and therefore the aforementioned receiving speed ispreferably employed.

The received undrawn filaments are continuously heat-drawn at a singlestage or multiple stages using rollers 1 to 4. The temperature of thedraw roller 3 is set to 70 to 125° C. The draw ratio is set so as tofall within the range of 3.0 to 6.0. Especially in order to attain thehigh tenacity and elongation of the spun-dyed textured polylactedfilament yarn of this invention and the excellent loftiness and theabrasion resistance when it is used as a carpet, it is importance that asufficiently drawn and oriented polylacted filament yarn is subjected tocrimping processing.

The sufficiently drawn and oriented polylacted filaments are heat-setwith the heat-set roller 4. The temperature of the heat-set roller 4 is100 to 150° C. Appropriately setting the temperature range of theheat-set roller 4 makes it possible to control the crystallization ofthe polylacted filaments, resulting in desired properties.

The drawn polylacted filaments are continuously introduced into thetexturing device 5 to give crimps to the filaments. The filament yarn 6textured with the texturing device 5 is cooled on the cooling drum 20.

The heated fluid is preferably heated air and the temperature is 90 to160° C.

Appropriate conditions are selected depending on the fineness,processing rate, etc., of the polylacted filament yarn.

Subsequently, the textured filament yarn is subjected to entangleprocess via the nozzle of the entangle processing device 21. Theentangling nozzle has normally 2 to 6 apertures and is configured toexecute entangle processing by spraying high pressure air of 0.2 to 0.5MPa onto the traveling textured filament yarn at an approximatelyrectangular angle.

Then, the polylacted textured filament yarn is rolled up onto a winder22. The winding is performed with a winding tensile force of 0.10cN/dtex or below.

As the pile yarn for the carpet according to the second invention, it ispreferable to use a non-twisted or twisted spun-dyed textured polylactedfilament yarn as a single yarn and/or two or more doubled and twistedyarn.

Concretely, the following (1) to (8) can be used as a pile yarn.

(1) a pile yarn which is a non-twisted spun-dyed textured polylactedfilament yarn (raw filament yarn)

(2) a pile yarn in which non-twisted spun-dyed textured polylactedfilament yarns are air-tangled

(3) a pile yarn in which two or more non-twisted spun-dyed texturedpolylacted filament yarns are twisted

(4) a pile yarn in which the spun-dyed textured polylacted filament yarnis twisted at the twist count of 50 to 250 T/m

(5) a pile yarn in which two or more of the twisted spun-dyed texturedpolylacted filament yarns are twisted

(6) a pile yarn in which a heat-set pile yarn of the spun-dyed texturedpolylacted filament yarn is subjected to a wet heat treatment and a dryheat treatment

(7) a pile yarn in which the dry heat treatment temperature of the pileyarn of the spun-dyed textured polylacted filament yarn is set to 90 to130° C.

(8) a pile yarn in which the wet heat treatment temperature of the pileyarn of the spun-dyed textured polylacted filament yarn is set to 80 to120° C.

By employing any one of the pile yarns or any combination thereof, acarpet using the spun-dyed textured polylacted filament yarn as a pileyarn can be manufactured.

In the pile yarn using the spun-dyed textured polylacted filament yarn,the color, the total fineness (dtex) of the pile yarn, the state(non-twisted yarn or twisted yarn) of the polylacted textured filamentyarn, the number of combined spun-dyed textured polylacted filamentyarns, and the conditions/status of the twisted yarn, etc., are decidedbased on the manufacturing standard of a carpet.

The spun-dyed textured polylacted filament yarn can be used in the formof a non-twisted filament yarn, or in the form of a combined filamentyarn in which a non-twisted filament yarn and other non-twisted filamentyarn are combined with an air tangling device, or can be used as it isor in the form of a twisted yarn.

The spun-dyed textured polylacted filament yarn according to the secondinvention can be used in the form of a twisted yarn (the twist count ispreferably 150 to 250 T/m), or can be used after twisting two or more oftwisted yarns (the twist count is preferably 50 to 200 T/m).

For example, using two or three spun-dyed textured polylacted filamentyarns, lower twisting and upper twisting are performed to obtain atwisted textured yarn. Thereafter, twist setting is executed with theheated air treatment of 100 to 125° C. or steam treatment of 90 to 115°C. in a vacuum equipment to thereby obtain a pile yarn for a carpet.

It is preferable that the average pile length of the carpet surfaceusing the pile yarn of the spun-dyed textured polylacted filament yarnis 5 to 15 mm, and the pile weight per unit area is 500 to 3,000 g/m².The carpet manufacturing method is not specifically limited, and can beany method for manufacturing, for example, a woven carpet, an embroidercarpet, an adhesive carpet and a knitted carpet. The configuration ofthe pile is not specifically limited, and can be any one ofconfigurations selected from a cut pile, a loop file, and a cut-and-loopfile depending on the required texture.

The average pile length of the spun-dyed textured polylacted filamentyarn formed into the carpet of the second invention is 5 to 15 mm,preferably 6.5 to 15 mm, more preferably 7.5 to 12 mm, still morepreferably 8 to 12 mm. If the average pile length is less than 5 mm, thebase fabric can be seen via the gaps of the pile surface. This resultsin deteriorated loftiness and bottom-out feeling at the time of usingthe carpet. If the average pile length exceeds 15 mm, although it isexcellent in loftiness and it looks good, the cost increases.Furthermore, the pile yarn becomes weak in drape, resulting ineasy-to-fall pile in use.

The weight per unit area of the pile of the carpet according to thesecond invention is 500 to 3,000 g/cm², more preferably 600 to 2,500g/m², still more preferably 800 to 2,200 g/m². If the weight per unitarea of the pile is less than 500 g/m², the backing can be seen via thegaps of the pile surface. This results in deteriorated loftiness andbottom-out feeling at the time of using the carpet. If the weight perunit area of the pile exceeds 3,000 g/m², although it is excellent inloftiness and it looks good, it becomes heavy, resulting inhard-to-handle carpet.

For example, in the case of tufting a pile yarn of the spun-dyedtextured polylacted filament yarn, the gauge is preferably 1/16 to ¼(the number of needles with 1 inch (2.54 cm) space), more preferably1/12 to ⅛. The stitch number is 25 to 70 stitch/10 cm, preferably 35 to65 stitch/10 cm, more preferably 46 to 65 stitch/10 cm.

The carpet using the spun-dyed textured polylacted filament yarn as apile yarn is subjected to a backing treatment to fix the pile yarn. Atthis time, the carpet will pass a drying step and a heat-set step toexert crimps inherent in the spun-dyed textured polylacted filament yarnnormally by a dry heat treatment and/or a vapor treatment, resulting ina carpet excellent in loftiness and giving no bottom-out feeling.

The carpet of the second invention uses the spun-dyed texturedpolylacted filament yarn as a pile yarn. If polylacted resin in theamount of 30 to 70 mass % is added to the base fabric, the backingresin, etc., constituting the carpet, the plant-percentage thereofincreases, resulting in a global environment friendly carpet whichincreases less carbon dioxide from the view point of environmentalprotection.

The pile abrasion amount of the carpet surface of the second inventionmeasured by a Taber type abrasion test (a test is performed according toa Taber type abrasion test defined by JIS L1096.8.17.3. An H-18 abrasionring is used, and the number of the abrasion is 2,500 times) is 5 to 30mass %. When the abrasion amount of the pile yarn by the Taber typeabrasion test is 5 to 30 mass %, a carpet excellent in abrasionresistance can be provided. It is preferable that the abrasion amount ofthe pile yarn is less than 5 mass %, which is, however, a numberpractically difficult to attain. If the abrasion amount of the pile yarnexceeds 30 mass %, the filament yarns gradually drop off from the carpetduring the use. As a result, the base fabric can be seen in due course,resulting in largely different appearance, which is not preferable.

The carpet using the spun-dyed textured polylacted filament yarn madefrom the above-specified plant-derived material is used as a pile yarncan be provided as a carpet excellent in loftiness and having voluminouslook. Furthermore, a carpet remarkably improved in abrasion resistanceand buckling resistance as compared with a carpet manufactured usingconventional polylacted filament yarns can be provided. The carpet canbe used as a carpet for various purposes in the fields of a roll carpet,a piece carpet, a tile carpet, an automobile carpet and an optioncarpet, and a household rug/mat, which can make use of thecharacteristics of the carpet of the invention.

Next, a carpet according to the third invention will be explained. Thecarpet of the third invention is a carpet using a pile yarn made of thespun-dyed textured polylacted filament yarn and the spun-dyed texturedsynthetic filament yarn, wherein the carpet meets the pile yarn abrasionamount of the carpet surface measured by a Taber type abrasion test (atest is performed according to a Taber type abrasion test defined by JISL1096.8.17.3. An H-18 abrasion ring is used, and the number of theabrasion is 5,000 times) is 5 to 30 mass %.

When the pile yarn abrasion amount of the surface by the Taber typeabrasion test is 5 to 30 mass %, a carpet excellent in abrasionresistance can be provided. It is ideal that the abrasion amount of thepile yarn is less than 5 mass %, which is, however, a number practicallydifficult to attain. If the abrasion amount of the pile yarn exceeds 30mass %, the filament yarns gradually drop of f from the carpet duringthe use. As a result, the base fabric can be seen in due course,resulting in largely different appearance, which is not preferable.

The method of using the spun-dyed textured polylacted filament yarn andthe spun-dyed textured synthetic filament yarn as a pile yarn is notspecifically limited. The pile yarn made of the spun-dyed texturedpolylacted filament yarns and the pile yarn made of the spun-dyedtextured synthetic filament yarns can be arranged every one or two rows(see FIG. 3). Alternatively, the spun-dyed textured polylacted filamentyarn and the spun-dyed textured synthetic filament yarn are combinedinto a composite yarn and this composite yarn can be used as a pile yarn(see FIG. 4).

The carpet manufacturing method is not specifically limited, and can beany method for manufacturing, for example, a woven carpet, an embroidercarpet, an adhesive carpet and a knitted carpet. The configuration ofthe pile is not specifically limited, and can be in the form of a cutpile, a loop file, or a cut-and-loop file.

The polylacted polymer constituting a polylacted resin composition as amaterial of the spun-dyed textured polylacted filament yarn ispolylacted in which lactide monomer containing L-lactide as a mainingredient is polymerized. It is preferable that 90 mass % or more ofthe lactide monomer is constituted by L-lactide. In other words,D-lactide can be contained in the lactate monomer in the range notexceeding 10 mass %. When the optical purity (optical purity ofL-lactide) of the lactide monomer to be used is 90% or more, the polymer(polylacted) becomes crystalline, which is preferable. When the opticalpurity of the lactide monomer to be used is 97% or more, the meltingpoint becomes about 170° C., which is more preferable. Polylactedpolymer in which components other than lactide are copolymerized can beused so long as the amount falls within the range which does not harmthe effects of the present invention. In the case of copolymerizingcomponents other than lactide, the lactide unit should be 70 mass % ormore but less than 100 mass % of the repeating unit of the polymermolecular chain, preferably 80 mass-0 or more but less than 100 mass %,more preferably 90 mass % or more but less than 100 mass %.

The relative viscosity (RV) of the spun-dyed textured polylactedfilament yarn is required to be 2.5 to 3.8. The relative viscosity is avalue measured using a mixed solution of 20° C.,phenol/tetrachloroethane=60/40 (mass ratio). If the relative viscosityis less than 2.5, sufficient tenacity and elongation cannot be given tothe polylacted textured filament yarn, and abrasion property appropriateto the carpet usage cannot be given thereto. On the other hand, if therelative viscosity exceeds 3.8, the melt viscosity becomes highexcessively. As a result, it is required to raise the spinningtemperature, resulting in decreased relative viscosity of the texturedpolylacted filament yarn which is extremely lower than a before-meltlevel thereof and also resulting in insufficiently improved tenacity. Inaddition, this also causes difficulty in spinning. It is more preferablethat the relative viscosity of the spun-dyed textured polylactedfilament yarn is 2.8 to 3.6.

Furthermore, the polylacted resin compound used as a material of thespun-dyed textured polylacted filament yarn contains a coloring agent inthe amount of 0.01 to 3 mass %. This concentration can give anappropriate color density to the textured filament yarn, resulting inimproved design property. If the concentration is set to 0.01 mass % ormore, generation of color shading due to the coloring agent irregularitycan be prevented. If it is set to 3 mass % or less, generation offilament yarn breakage can be sufficiently prevented. It is especiallypreferable that the ratio of content of the coloring agent is 0.05 to1.0 mass %. Furthermore, the coloring agent can be used together with adispersing agent normally used (e.g., olefin series compound).

In addition to polymer (including polymer particles) other thanpolylacted polymer, it should be noted that any additive agent, such as,e.g., delustering agent, plasticizing agent, fire retardant, antistaticagent, odor eliminating agent, antibacterial agent, antioxidant agent,heat resisting agent, light resistant agent, and ultraviolet [UV]absorber, can be added to the polylacted resin composition so long asthe amount falls within the range which does not harm the effects of thepresent invention.

The carpet of the third invention using the spun-dyed texturedpolylacted filament yarn as a pile yarn is a carpet in which thespun-dyed textured polylacted filament yarn used as the pile yarn meetsall of the following characteristics (1) to (7):

(1) a filament has an approximately circular or circular cross-section(i.e., circular cross-sectional filament yarn). This cross-sectionalconfiguration gives abrasion resistance to the filament yarn. It ispreferable that the cross-sectional configuration of the filament is anapproximately circular or circular having a degree of deformation lessthan 1.5, wherein the degree of deformation is expressed by a ratio(B/A) of a diameter B of an circumscribed circle of the filamentcross-section to a diameter A of a inscribed circle of the filamentcross-section (see FIG. 2). If the degree of deformation exceeds 1.5,the covering property of the textured polylacted filament yarn can beimproved. However, due to the large degree of deformation, the hard andbrittle properties inherent in polylacted polymer tend to be exerted,resulting in deteriorated abrasion resistance of the filament yarn, andtherefore it is not preferable;

(2) relative viscosity (RV) is 2.5 to 3.8;

(3) tenacity is 1.75 to 3.5 cN/dtex;

(4) elongation is 35 to 60 W;

(5) a filament fineness is 2.5 to 25 dtex;

(6) hot water shrinkage ratio is 2 to 8%; and

(7) dry heat crimp ratio is 5 to 25%.

The tenacity of the spun-dyed textured polylacted filament yarn is 1.75to 3.5 cN/dtex. If the tenacity of the textured filament yarn is lessthan 1.75 cN/dtex, when the textured filament yarn is used as a carpet,the abrasion resistance becomes insufficient, and a part of the texturedfilament yarn may sometimes be worn out. It is preferable that thetenacity of the spun-dyed textured polylacted filament yarn is 2.0 to3.25 cN/dtex, more preferably 2.25 to 3.25 cN/dtex. The elongation ofthe spun-dyed textured polylacted filament yarn is 35 to 60%. If theelongation of the textured filament yarn is less than 35%, when thetextured filament yarn is used as a carpet, the abrasion resistancebecomes insufficient, and a part of the textured filament yarn maysometimes be worn out. It is preferable that the elongation of thespun-dyed textured polylacted filament yarn is 40 to 55%.

If the tenacity of the spun-dyed textured polylacted filament yarn is2.0 to 3.25 cN/dtex and the elongation of the spun-dyed texturedpolylacted filament yarn is 40 to 55%, the filament yarn can have highertoughness, which is preferable. However, raising of the tenacitygenerally causes deterioration of elongation. Even if the elongation isset to 35% or more, the tenacity is merely 3.5 cN/dtex. Furthermore, ifthe elongation exceeds 60%, the tenacity cannot be increased so as toexceed 1.75 cN/dtex.

Furthermore, the total fineness of the spun-dyed textured polylactedfilament yarn preferably falls within the range of 500 to 3,500 dtex. Solong as it falls within the range, it becomes an optimal spun-dyedtextured filament yarn for a tufted carpet, but not limited to suchusage. Among other things, it is preferable that the total fineness ofthe spun-dyed textured polylacted filament yarn falls within the rage of1,000 to 3,000 dtex. The filament fineness of the spun-dyed texturedpolylacted filament yarn falls within the range of 2.5 to 25 dtex. Ifthe filament fineness is less than 2.5 dtex, it becomes difficult toperform the yarn-making stably, and the loftiness of the carpet formedusing the textured filament yarns becomes insufficient. If the filamentfineness exceeds 25 dtex, it become difficult to obtain the filamentyarn property of the spun-dyed textured polylacted filament yarn and thehard and brittle properties inherent in polylacted polymer tend to beexerted, resulting in deteriorated abrasion resistance of the filamentyarn. This tendency becomes prominent as the degree of deformation ofthe cross-section of the polylacted filament yarn increases in the samefilament fineness. Accordingly, the smaller degree of deformation of thefilament is preferable. It is preferable that the filament fineness ofthe 1 spun-dyed textured polylacted filament yarn falls within the rangeof 4 to 20 dtex, more preferably 5 to 15 dtex. In cases where thefilament fineness falls within the range of 2.5 to 25 dtex, the soft andbrittle property of the polylacted polymer can be weakened and thetenacity and the elongation of the spun-dyed textured polylactedfilament yarn can be further improved and that the abrasion resistanceof a carpet using the spun-dyed textured polylacted filament yarn canalso be improved.

The hot water shrinkage ratio of the spun-dyed textured polylactedfilament yarn falls within the range of 2 to 8%. If the hot watershrinkage ratio is less than 2%, the crystallinity of the spun-dyedtextured polylacted filament yarn becomes higher. As a result, the hardand brittle property of the polylacted polymer will be easily exerted,resulting in poor balanced tenacity and elongation and insufficientabrasion resistance as a carpet. On the other hand, if the hot watershrinkage ratio exceeds 8%, there are problems that filament yarnshrinkage occurs at the time of the heat-set treatment and it becomesdifficult to administrate each carpet manufacturing step. Above allthings, it is preferable that the hot water shrinkage ratio of thespun-dyed textured polylacted filament yarn falls within the range of 3to 6%.

The hot water shrinkage ratio of the spun-dyed textured polylactedfilament yarn falls within the range of 5 to 25%. If the hot watershrinkage ratio is less than 5%, the crystallinity of the spun-dyedtextured polylacted filament yarn becomes higher. As a result, the hardand brittle property of the polylacted polymer will be easily exerted,resulting in poor balanced tenacity and elongation and insufficientabrasion resistance as a carpet. On the other hand, if the hot watershrinkage ratio exceeds 25%, there are problems that filament yarnshrinkage occurs at the time of the heat-set treatment and it becomesdifficult to administrate each carpet manufacturing step. Above allthings, it is preferable that the hot water shrinkage ratio of thespun-dyed textured polylacted filament yarn falls within the range of 8to 20%.

As the coloring agent for the spun-dyed textured polylacted filamentyarn, for example, an inorganic pigment and an organic pigment can beexemplified. But the coloring agent is not specifically limited theretoso long as it gives a color to the textured filament yarn. As thecoloring agent, for example, at least one of pigments selected from thegroup comprising carbon black, inorganic pigment such as, e.g.,oxidization series organic pigment, ferrocyanide inorganic pigment,silicate inorganic pigment, carbonate inorganic pigment, and phosphateinorganic pigment, phthalocyanine series organic pigment, peryleneseries organic pigment, and isoindolinon series organic pigment is used.

The spun-dyed textured polylacted filament yarn used in the thirdinvention is preferably a spun-dyed textured polyester filament yarn, aspun-dyed textured nylon filament yarn, or a spun-dyed texturedpolypropylene filament yarn. Considering environmental protections suchas recyclability, the most preferable one is a spun-dyed texturedpolyester filament yarn. Combining a spun-dyed textured syntheticfilament yarn made from a plant-derived material and a spun-dyedtextured synthetic filament yarn made from a petroleum-derived materialmakes it possible to further improve the abrasion resistance and theloftiness as compared with a carpet only using a spun-dyed texturedpolylacted filament yarn made from a plant-derived material.

The pile yarn for a carpet of the third invention can be used as asingle yarn and/or two or more of twisted yarns of a non-twisted yarnand/or a twisted yarn made of a spun-dyed textured polylacted filamentyarns made from a plant-derived material and a spun-dyed texturedsynthetic filament yarns made from petroleum-derived material.Alternatively, the spun-dyed textured polylacted filament yarn and thespun-dyed textured synthetic filament yarn are combined into a compositeyarn and this composite yarn can be used as a pile yarn (see FIG. 4).

Concretely, using the spun-dyed textured polylacted filament yarns madefrom a plant-derived material and the spun-dyed textured syntheticfilament yarns made from petroleum-derived material, the following (1)to (7) can be used as a pile yarn.

(1) the non-twisted textured filament yarn (raw filament yarn) can beused as a pile yarn

(2) by air-tangling the non-twisted filament yarns, it can be used as apile yarn

(3) by twisting them, it can be used as a pile yarn

(4) by twisting them at the twist count of 50 to 250 T/m, it can be usedas a pile yarn

(5) by twisting two or more of them, it can be used as a pile yarn

(6) a pile yarn in which a heat-set pile yarn of the spun-dyed texturedpolylacted filament yarn is subjected to a wet heat treatment and a dryheat treatment

(7) by combining the spun-dyed textured polylacted filament yarn and thespun-dyed textured synthetic filament yarn and heat-setting thecomposite yarn, it can be used as a pile yarn.

By arbitrarily selectively employing the aforementioned spun-dyedtextured polylacted filament yarns made from a plant-derived materialand a spun-dyed textured synthetic filament yarns made frompetroleum-derived material, a carpet improved in abrasion resistance canbe manufactured.

In the carpet of the third invention, it is preferable that the carpetuses a pile yarn made of a spun-dyed textured polylacted filament yarnsmade from a plant-derived material and a spun-dyed textured syntheticfilament yarns made from petroleum-derived material and that the carpetsurface is 5 to 15 mm in the average pile length, and 500 to 3,500 g/m²in pile weight per unit area.

When a spun-dyed textured polylacted filament yarns made from aplant-derived material and a spun-dyed textured synthetic filament yarnsmade from petroleum-derived material are used as a pile yarn, theaverage pile length is 5 to 15 mm, preferably 6.5 to 15 mm, morepreferably 7.5 to 12 mm, still more preferably 8 to 12 mm. If theaverage pile length is less than 5 mm, the base fabric can be seen viathe gaps of the pile surface. This results in deteriorated loftiness andbottom-out feeling at the time of using the carpet. If the average pilelength exceeds 15 mm, although it is excellent in loftiness and it looksgood, the cost increases. Furthermore, the pile yarn becomes weak indrape, resulting in easy-to-fall pile in use.

The weight per unit area of the pile of the carpet is 500 to 3,500g/cm², more preferably 600 to 3,200 g/m², still more preferably 800 to3,000 g/m². If the weight per unit area of the pile is less than 500g/m², the backing can be seen via the gaps of the pile surface. Thisresults in deteriorated loftiness and bottom-out feeling at the time ofusing the carpet. If the weight per unit area of the pile exceeds 3,500g/m², although it is excellent in loftiness and it looks good, itbecomes heavy, resulting in hard-to-handle carpet.

For example, in the case of tufting a pile yarn made of a spun-dyedtextured polylacted filament yarns made from a plant-derived materialand a spun-dyed textured synthetic filament yarns made frompetroleum-derived material, the gauge is preferably 1/16 to ¼ (thenumber of needles with 1 inch (2.54 cm) space), more preferably 1/12 to⅛. The stitch number is 20 to 70 stitch/10 cm, preferably 25 to 65stitch/10 cm, more preferably 35 to 60 stitch/10 cm. The optimal stitchnumber is 40 to 60 stitch/10 cm.

The carpet using a spun-dyed textured polylacted filament yarns madefrom a plant-derived material and a spun-dyed textured syntheticfilament yarns made from petroleum-derived material as a pile yarn issubjected to a backing treatment to fix the pile yarn. At this time, thecarpet will pass a drying step and a heat-set step to exert crimpsinherent in the a spun-dyed textured polylacted filament yarns made froma plant-derived material and a spun-dyed textured synthetic filamentyarns made from petroleum-derived material normally by a dry heattreatment and/or a vapor treatment, resulting in a carpet excellent inloftiness and giving no bottom-out feeling.

The tufted carpet using a spun-dyed textured polylacted filament yarnsmade from a plant-derived material and a spun-dyed textured syntheticfilament yarns made from petroleum-derived material as a pile yarn canbe provided as a carpet excellent in loftiness and having voluminouslook. Furthermore, a carpet remarkably improved in abrasion resistanceand buckling resistance as compared with a carpet manufactured usingconventional polylacted filament yarns can be provided.

The carpet using a spun-dyed textured polylacted filament yarns madefrom a plant-derived material and a spun-dyed textured syntheticfilament yarns made from petroleum-derived material as a pile yarnaccording to the third invention can be used as a carpet for variouspurposes in the fields of a roll carpet, a piece carpet, a tile carpet,an automobile carpet and an option carpet, and a household lag/mat,which can make use of the characteristics of the carpet of theinvention.

The carpet of the third invention uses the spun-dyed textured polylactedfilament yarn as a part (especially as a main portion) of a pile yarn.If polylacted resin in the amount of 30 to 70 mass % is added to thebase fabric, the backing resin, etc., constituting the carpet, theplant-percentage thereof increases, resulting in a global environmentfriendly carpet which increases less carbon dioxide from the view pointof environmental protection.

Hereinafter, a concrete manufacturing method of the spun-dyed texturedpolylacted filament yarn required in the third invention will beexplained, but not limited thereto.

As the polylacted monomer for use in manufacturing the spun-dyedtextured polylacted filament yarn, polylacted monomer having a relativeviscosity (RV) of 2.5 to 3.8 measured as a mixed solution of 20° C.,phenol/tetrachloroethane=60/40 (mass ratio) is used. In the carpet usageof this invention, since the tenacity and the elongation of the texturedfilament yarn, the crimping characteristics and the abrasion resistanceare required, polylacted polymer having a high molecular weight, i.e.,polymer having the above-specified relative viscosity, will be required.

As the inorganic pigment and the organic pigment to be used as acoloring agent for the spun-dyed textured polylacted filament yarn, atleast one pigment selected from the above-specified compounds is used.After adding a coloring agent to the polylacted polymer, yarn-making canbe performed.

Polylacted polymer in which the aforementioned polylacted polymer andthe coloring agent are mixed at a certain ratio with a mixing device issupplied to a biaxial extruder 12 with vents 13 and molten and extrudedfrom the spinning 15 via a spinning pack.

The spun-dyed textured polylacted filament yarn has an approximatelycircular or circular cross-sectional configuration. The degree ofdeformation of the filament cross-section expressed by a ratio (B/A) ofa diameter B of an circumscribed circle of the filament cross-section toa diameter A of a inscribed circle of the filament cross-section ispreferably less than 1.5.

Next, the spun filament is cooled and solidified with quench air of thecooling device 16.

After applying a lubricant to the cooled and solidified spun filament,the filament yarn is received with the receiving roller 1 rotating at apredetermined rotational rate.

The rotational speed of the receiving roller 1 is 400 to 1,000 m/mim.

The manufacturing method of the textured filament yarn according to thethird invention is characterized in a direct spinning extension andcrimping process, and therefore the aforementioned receiving speed ispreferably employed.

The received undrawn filament yarn filament is continuously heat-drawnat a single stage or multiple stages using rollers 1 to 4. Thetemperature of the draw roller 3 is set to 70 to 125° C. The draw ratiois set so as to fall within the range of 3.0 to 6.0. Especially in orderto attain the high tenacity and elongation of the spun-dyed texturedpolylacted filament yarn of this invention and the excellent loftinessand the abrasion resistance when it is used as a carpet, it isimportance that a sufficiently drawn and oriented polylacted filamentyarn is subjected to texturing processing.

The sufficiently drawn and oriented polylacted filament yarn is heat-setwith the heat-set roller 4. The temperature of the heat-set roller 4 is100 to 150° C. Appropriately setting the temperature range of theheat-set roller 4 makes it possible to control the crystallization ofthe polylacted filament yarn, resulting in desired properties.

The drawn polylacted filament yarn is continuously introduced into thetexturing device 5 to give crimps to the filament yarn. The filamentyarn 6 textured with the texturing device 5 is cooled on the coolingdrum 20.

The heated fluid is preferably heated air and the temperature is 90 to160° C.

Appropriate conditions are selected depending on the fineness,processing rate, etc., of the polylacted filament yarn.

Subsequently, the textured filament yarn is subjected to entangleprocess via the nozzle of the entangle processing device 21. Theconfounding nozzle has normally 2 to 6 apertures and is configured toexecute entangle process by spraying high pressure air of 0.2 to 0.5 MPaonto the traveling textured filament yarn at an approximatelyrectangular angle.

Then, the polylacted textured filament yarn is rolled up onto a winder22. The winding is performed with a winding tensile force of 0.10cN/dtex or below.

Next, the manufacturing method of the pile yarn for the carpet of thethird invention will be explained. The pile yarn for a carpet of thethird invention can be used as a single yarn and/or two or more oftwisted yarns of a non-twisted yarn and/or a twisted yarn made of aspun-dyed textured polylacted filament yarns made from a plant-derivedmaterial and a spun-dyed textured synthetic filament yarns made frompetroleum-derived material.

Alternatively, the spun-dyed textured polylacted filament yarn and thespun-dyed textured synthetic filament yarn are combined into a compositeyarn and this composite yarn can be used as a pile yarn.

In the pile yarn using both the textured filament yarns, the color, thetotal fineness (dtex) of the pile yarn, the state (non-twisted yarn ortwisted yarn) of the polylacted textured filament yarn, the number ofcombined textured filament yarns, and the conditions/status of thetwisted yarn, etc., are decided based on the manufacturing standard of atufted carpet.

Both the textured filament yarns can be used in the form of anon-twisted filament yarn, or in the form of a combined filament yarn inwhich a non-twisted filament yarn and other non-twisted filament yarnare combined with an air tangling device, or can be used as it is or inthe form of a twisted yarn.

Both the textured filament yarns can be used in the form of a twistedyarn (the twist count is preferably 150 to 250 T/m), or can be usedafter twisting two or more of twisted yarns (the twist count ispreferably 50 to 200 T/m).

For example, using two or three spun-dyed textured polylacted filamentyarns, lower twisting (180 T/m) and upper twisting (180 T/m) areperformed to obtain a twisted textured yarn. Thereafter, twist settingis executed with the heated air treatment of 100 to 125° C. or steamtreatment of 90 to 115° C. in a vacuum equipment to thereby obtain apile yarn for a carpet.

EXAMPLES

Next, concrete examples of this invention will be explained, but itshould be understood that the invention is not specifically limited tothese examples.

Initially, a concrete example of the first invention will be explained.

Example 1

Using the manufacturing device shown in FIG. 1, a polylacted texturedfilament yarn was manufactured. In detail, polylacted chips (polymer oflactide monomer consisting of L-lactide 98 mass % and D-lactide 2 mass%, weight-average molecular weight: 140,000, relative viscosity: 3.2;glass transition temperature Tg: 57° C., melting point: 170° C.,temperature of a softening point Ts: 130° C., crystallizationtemperature Tc: 115° C.) in the amount of 100 mass parts were thrown inthrough the polylacted chips inlet 10 and carbon black master batch(including the aforementioned polylacted polymer: 75 mass %, carbonblack: 25 mass %) 4 mass parts were thrown in through the coloring agentinlet 11. While expelling any remaining air, they were melt-blended inthe biaxial extruder 12 with vents 13 at 230° C. Thereafter, they wereextruded through a total of 64 holes each having a circularcross-section (round circular cross-section) of the spinning nozzle 15attached to the tip of the biaxial extruder 12 into filament yarnssimultaneously from three nozzles.

Next, the spun filaments were cooled and solidified with quench air (20°C. 70% RH) from the quench air blowing apparatus 16 to thereby obtain atotal of 192 multi-filaments each having a circular cross-section. Then,a lubricant was applied to the filaments with the lubricant applyingapparatus 17, and then the filaments were gathered and received by thenon-heated receiving roller 1 rotating at a rotational rate of 462m/min. Then, the filaments were pre-heated with the pre-heating roller 2set to a rotational rate of 462 m/min. and a temperature of 70° C.

Thereafter, the spun filaments were introduced to the draw roller 3 setto a rotational rate of 489 m/min. and a temperature of 105° C. and theheat-set roller 3 set to a rotational rate of 2,200 m/min. and atemperature of 120° C. to execute drawing. The draw ratio was 4.5. Thetemperature of the heat-set roller 4 was set to 120° C. lower than thetemperature of a softening point Ts of the polylacted polymer.

Next, the heat-set spun filaments were introduced in the texturingdevice 5 to bring heated and pressurized air of 110° C. and 0.6 MPa intocontact with the filaments to give crimps to the filaments. The texturedfilament yarns were cooled to 30° C. with a cooling drum 20. Thetemperature of the heated and pressurized air was set to 110° C. lowerthan the crystallization temperature Tc of the polylacted polymer. Then,the textured filament yarns were subjected to entangle processing of 30counts/m with the entangle processing device 21 and wounded on thewinder 22 with winding tensile force of 0.05 cN/dtex and at therotational rate of 1,910 m/min. Thus, a spun-dyed textured syntheticfilament yarn was obtained.

The obtained spun-dyed textured polylacted filament yarn was a circularcross-sectional filament yarn having a total fineness of 1,448 dtex/192filament (a filament fineness: 7.5 dtex), relative viscosity of 3.0,tenacity of 3.12 cN/dtex, elongation of 46.6%, hot water shrinkage ratioof 4.5%, and dry heat crimp ratio of 11.2%.

Using two obtained the spun-dyed textured polylacted filament yarns,lower twisting and upper twisting were executed at the twist count of180 times/m to obtain a twisted yarn. Thereafter, the twisted yarn wassubjected to a heated air treatment at 115° C. to fix the twists tothereby obtain a pile yarn for a carpet. Using this pile yarn, a tuftedcarpet equipped with cut piles having a standard of gauge: 1/10 (2.54cm/10 stitches), stitch: 48 pieces/10 cm, pile length: 10 mm, and pileportion weight per unit area: 1,500 g/m² was obtained.

Example 2

Using the manufacturing device shown in FIG. 1, a polylacted texturedfilament yarn was manufactured. In detail, polylacted chips (polymer oflactide monomer consisting of L-lactide 98 mass % and D-lactide 2 mass%, weight-average molecular weight: 140,000, relative viscosity: 3.2;glass transition temperature Tg: 57° C., melting point: 170° C.,temperature of a softening point Ts: 130° C., crystallizationtemperature Tc: 115° C.) in the amount of 100 mass parts were thrown inthrough the polylacted chips inlet 10 and carbon black master batch(including the aforementioned polylacted: 75 mass %, carbon black: 25mass %) in the amount of 4 mass parts were thrown in through thecoloring agent inlet 11. While expelling any remaining air, they weremelt-blended in the biaxial extruder 12 with vents 13 at 230° C.Thereafter, they were extruded through a total of 64 holes each having acircular cross-section (round circular cross-section) of the spinningnozzle 15 attached to the tip of the biaxial extruder 12 into filamentssimultaneously from three nozzles.

Next, the spun filaments were cooled and solidified with quench air (20°C. 70% RH) from the quench air blowing apparatus 16 to thereby obtain atotal of 192 multi-filaments each having a circular cross-section. Then,a lubricant was applied to the filaments with the lubricant applyingapparatus 17, and then the filaments were gathered and received by thenon-heated receiving roller 1 rotating at a rotational rate of 510m/min. Then, the filaments were pre-heated with the pre-heating roller 2set to a rotational rate of 516 m/min. and a temperature of 95° C.

Thereafter, the spun filaments were introduced to the draw roller 3 setto a rotational rate of 524 m/min. and a temperature of 110° C. and theheat-set roller 3 set to a rotational rate of 2,200 m/min. and atemperature of 125° C. to execute drawing. The draw ratio was 4.3. Thetemperature of the heat-set roller 4 was set to 125° C. lower than thetemperature of a softening point Ts of the polylacted polymer.

Next, the heat-set spun filaments were introduced in the texturingdevice 5 to bring heated and pressurized air of 115° C. and 0.6 MPa intocontact with the filament yarns to give crimps to the filaments. Thetextured filament yarn was cooled to 30° C. with a cooling drum 20. Thetemperature of the heated and pressurized air was set to the same 115°C. as the crystallization temperature Tc of the polylacted polymer.Then, the textured filament yarn was subjected to entangle processing of25 pieces/m with the entangle processing device 21 and wounded on thewinder 22 with winding tensile tenacity of 0.05 cN/dtex and at therotational rate of 1,636 m/min. Thus, a spun-dyed textured syntheticfilament yarn was obtained.

The obtained spun-dyed textured polylacted filament yarn was a circularcross-sectional filament yarn having a total fineness of 3,200 dtex/192filament (a filament fineness: 16.7 dtex), relative viscosity of 3.0,tenacity of 1.84 cN/dtex, elongation of 53.1%, hot water shrinkage ratioof 3.8%, and dry heat crimp ratio of 12.3%.

Using two obtained the spun-dyed textured synthetic filament yarns,lower twisting and upper twisting were executed at the twist count of180 times/m to obtain a twisted yarn. Thereafter, the twisted yarn wassubjected to a heat treatment by a steam vapor of 95° C. to fix thetwists to thereby obtain a pile yarn for a carpet. Using this pile yarn,a tufted carpet equipped with cut piles having a standard of gauge: 1/10(2.54 cm/10 stitches), stitch: 44 pieces/10 cm, pile length: 10 mm, andpile portion weight per unit area: 1,500 g/m² was obtained.

Example 3

A spun-dyed polylacted textured filament yarn was manufactured in thesame manner as in Example 1 except that a filament yarn comprising afilament having an approximately circular cross-section having a degreeof deformation of 1.4 was used. The characteristics of the obtainedspun-dyed polylacted textured filament yarn are shown in Table 1.Furthermore, using the obtained spun-dyed polylacted textured filamentyarn, a tufted carpet was obtained in the same manner as in Example 1.

Example 4

A spun-dyed polylacted textured filament yarn was manufactured in thesame manner as in Example 1 except that a filament yarn comprising afilament having an approximately circular cross-section having a degreeof deformation of 4.1 was used. The characteristics of the obtainedspun-dyed polylacted textured filament yarn are shown in Table 1.Furthermore, using the obtained spun-dyed polylacted textured filamentyarn, a tufted carpet was obtained in the same manner as in Example 1.

Example 5, Comparative Example 2

A spun-dyed polylacted textured filament yarn was manufactured in thesame manner as in Example 1 except that the manufacturing was executedunder the conditions shown in Table 1. The characteristics of theobtained spun-dyed polylacted textured filament yarn are shown inTable 1. Furthermore, using the obtained spun-dyed polylacted texturedfilament yarn, a tufted carpet was obtained in the same manner as inExample 1.

Comparative Example 1

A spun-dyed polylacted textured filament yarn was manufactured in thesame manner as in Example 1 except that a spinning nozzle equipped witha total of 32 holes each having an approximately Y-shape incross-section was used as a spinning 15.

The obtained spun-dyed polylacted textured filament yarn was a modifiedcross-section filament yarn having total fineness of 1,100 dtex/96filaments (a filament fineness: 11.5 dtex) and a degree of deformationof 2.2. The relative viscosity was 3.0, the tenacity was 1.54 cN/dtex,the elongation was 32.0%, the hot water shrinkage ratio was 4.1%, andthe dry heat crimp ratio was 12.3%.

The obtained three textured polylacted filament yarns were twisted intoa twisted yarn, and then the twisted yarn was subjected to a heated airtreatment at 115° C. to fix the twists to thereby obtain a pile yarn fora carpet. Using this pile yarn, a tufted carpet equipped with cut pileshaving a standard of gauge: 1/10 (2.54 cm/10 stitches), stitch: 44pieces/10 cm, pile length: 10 mm, and pile portion weight per unit area:1,500 g/m² was obtained.

Comparative Example 3

Polylacted chips (polymer of lactide monomer consisting of L-lactide 98mass % and D-lactide 2 mass %, weight-average molecular weight: 220,000,relative viscosity: 4.0) in the amount of 100 mass parts were thrown inthrough the polylacted chips inlet 10 of the manufacturing apparatusshown in FIG. 1 and carbon black master batch (including theaforementioned polylacted polymer: 75 mass %, carbon black: 25 mass %)in the amount of 4 mass parts were thrown in through the coloring agentinlet 11. While expelling any remaining air, they were melt-blended inthe biaxial extruder 12 with vents 13 at 230° C. Since the meltviscosity of the polylacted polymer at the outlet of the biaxialextruder 12 was excessively high, the pressure loss in the polymer tubehaving a polymer tube temperature of 225° C. up to the spinning head 14was large, which caused remarkable irregular discharge rate of thepolylacted polymer at the outlet of the spinning head 14. Therefore, thetemperature of the biaxial extruder 12 was set to 235° C. and thepolymer tube temperature was set to 250° C. As a result, the dischargeamount of the polylacted polymer was stabilized, but the polylactedpolymer became yellow at the outlet of the spinning head 14.Furthermore, smoke which was assumed due to thermal decomposition wasgenerated, resulting in poor spinning.

TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Com. Ex 1 Com. Ex. 2 ManufacturingTemp. of quench air (° C.) 20 20 20 20 20 20 20 conditions Temp. ofpre-heating roller (° C.) 70 100 70 70 70 70 70 Temp. of draw roller (°C.) 105 110 105 105 105 105 105 Draw ratio (times) 4.5 4.3 4.5 4.5 4.54.5 4.5 Temp. of heat-set roller S(° C.) 120 125 120 120 120 120 140Temp. of heated fluid R(° C.) 110 115 110 110 130 110 105 S − R (° C.)10 10 10 10 −10 10 35 Cooling temp. of filament yarn 30 30 30 30 30 3030 by cooling drum (° C.) Characteristics Relative viscosity 3.0 3.0 3.03.0 3.0 3.0 3.0 of textured Degree of deformation 1 (circular 1(circular 1.4 1 (circular 1 (circular 2.2 1 (circular filament yarncross- cross- cross- cross- cross- section) section) section) section)section) Tenacity (cN/dtex) 3.12 1.84 2.34 2.72 1.94 1.54 1.01Elongation (%) 46.6 53.1 46.0 43.5 42.2 32.0 28.4 Total fineness (dtex)1448 3200 1449 1179 1459 1100 1452 A filament fineness (%) 7.5 16.7 7.54.1 7.6 11.5 7.6 hot water shrinkage ratio (%) 4.5 3.8 5.1 5.8 2.5 4.11.6 dry heat crimp ratio (%) 11.2 12.3 11.8 10.8 12.5 12.3 12.7Evaluation of Loftiness ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ Carpet property Abrasionresistance ⊚ ◯ ⊚ ⊚ ◯ X X

Characteristics of each spun-dyed polylacted textured filament yarn weremeasured based on the following measuring methods. The loftiness and theabrasion resistance of the obtained tufted carpet were evaluated basedon the following evaluation methods. These results are shown in Table 1.

<Relative Viscosity Measuring Method>

Specimens were dissolved in a mixed solution ofphenol/tetrachloroethane=60/40 (mass ratio) so that the concentrationbecame 1 g/dL, and the relative viscosity was measured using anubbelohde viscosity tube at 20° C.

<Weight-Average Molecular Weight Measuring Method>

Specimens were dissolved in chloroform so that the concentration became10 mg/mL, and GPC analysis was executed using chloroform as a solventwith a measuring device HLC8120GPC manufactured by TOSO Corporation tomeasure the weight-average molecular weight Mw. An RI (infraredspectrograph) was used as a detector, and polystyrene was used as areference material of a molecular weight.

<Ratio Measurement of L-Lactide>

Polylacted chips were hydrolyzed and the ratio of L-lactide was measuredusing methanol sodium hydroxide solution as a solvent with ahigh-performance liquid chromatography (HPLC: LC10AD type manufacturedby SHIMADZU Corporation).

<Degree of Deformation Evaluation Method>

After cutting a filament, a diameter A of an inscribed circle of thecross-section of the filament and a diameter B of a circumscribed circlethereof were measured using an optical microscope. The value B/A wasdefined as the degree of deformation (see FIG. 2).

<Tenacity and Elongation Measuring Method>

Using a tensile testing machine TENSORAPID3 manufactured by USTER Corp.,the tenacity cN and the elongation % were measured under the conditionsof specimen length: 25 cm and the tensile rate: 30 cm/min. The tenacitycN/dtex is a value obtained by dividing the tenacity cN by the totalfineness.

<Fineness Measuring Method>

Fineness was measured in accordance with JIS L1013.

<Hot Water Shrinkage Ratio Measuring Method>

Hot water shrinkage ratio % was measured according to a JIS L1013 skeinshrinkage percentage (A method). Initially, a spun-dyed polylactedtextured filament yarn was took off from a bobbin package to obtain aspecimen. A load for giving a tensile force of a total finenessdtex×0.882 mM (90 mg/dtex) was applied to the specimen filament yarn andheld for 10 seconds. Thereafter, the specimen length Ls1 was measured.In an unloaded condition, it was immersed in hot water having atemperature of 98° C. for 30 minutes, and then dried naturally for anentire day. This dried textured filament yarn was a hot water treatedspun-dyed polylacted textured filament yarn. A load for giving a tensileforce of a total fineness dtex×0.882 mM (90 mg/dtex) was applied to thehot water treated spun-dyed polylacted textured filament yarn and heldfor 10 seconds. Thereafter, the specimen length Ls2 was measured.

Hot water shrinkage ratio %={(Ls1−Ls2)/Ls1}×100

From the above equation, the hot water shrinkage ratio % was obtained.

<Dry Heat Crimp Ratio Measuring Method>

A spun-dyed polylacted textured filament yarn took off from a bobbinpackage was treated with heated air of 100° C. for 10 minutes under noload and naturally left to obtain a dry heat treated spun-dyed texturedpolylacted filament yarn. After applying a certain load to the dry heattreated spun-dyed textured polylacted filament yarn to give a tensileforce of a total fineness dtex×0.882 mN (90 mg/detx) for 10 seconds, thespecimen length Lc1 was measured. Subsequently, a certain load wasapplied to the dry heat treated spun-dyed textured polylacted filamentyarn to give a tensile force of a total fineness dtex×0.0176 mN (1.8mg/detx) for 10 seconds, and then the specimen length was measured.

Dry heat crimp ratio measuring method %={(Lc1−Lc2)/Lc1}×100

From the above equation, the dry heat crimp ratio % was obtained.

<Bulkiness Evaluation>

When observed the carpet from the right above, the state in which thebase fabric could be observed via the gaps of the pile surface wasvisually evaluated as follows: “∪” denotes that the base fabric washardly observed; “∘” denotes that the base fabric was observed to somedegree; and “x” denotes that the base fabric was clearly observed.

<Abrasion Resistance Evaluation>

The abrasion resistance of the carpet was evaluated using a Taber typeabrasion test machine defined by JIS L1096.17.3. In detail, using anH-18 abrasion ring, a load of 9.8 N was applied to this abrasion ringand a test stand was rotated 1,000 times to wear the specimen. Theabrasion state was visually observed to evaluate as follows: “∪” denotesthat abrasion rate was very low; “∘” denotes that abrasion rate was low:“Δ” denotes that abrasion was occurred to some extent; and “x” denotesthat abrasion rate was high.

As will be apparent from Table 1, in the carpets of Examples 1 to 5using the spun-dyed polylacted textured filament yarn of the firstinvention, sufficient bulkiness was obtained and the abrasion resistancewas excellent. To the contrary, in the carpet of Comparative Examples 1and 2, the abrasion resistance was poor.

Next, concrete examples of the second invention will be explained.Characteristics of each spun-dyed polylacted textured filament yarn weremeasured based on the aforementioned measuring methods. The loftinessand the abrasion resistance of the obtained tufted carpet were evaluatedbased on the following evaluation methods.

[Loftiness]

When observed the carpet from the right above, the carpet was visuallyobserved in a state in which the base fabric could be observed via thegaps of the pile surface and evaluated as follows: “∪” denotes that thebase fabric could not be observed; “∘” denotes that the base fabriccould be hardly observed; “Δ” denotes that the base fabric could beobserved to some degree; and “x” denotes that the base fabric could beclearly observed.

[Abrasion Resistance Evaluation]

The evaluation of the abrasion resistance of the carpet was executedaccording to the Taber type abrasion test (defined by the Taber typeabrasion test (JIS L1096.8.17.3, 2004 Edition), where an H-18 abrasionring was used, and the number of abrasion was 2,500 times). That is,using an H-18 abrasion ring, a load of 9.8 N was applied to eachabrasion ring and a test stand was rotated 2,500 times to wear thespecimen. The abrasion amount of the pile yarn was measured. From thefollowing equation, the Taber abrasion amount (mass %) was obtained.

Taber abrasion amount (mass %)=pile dropped-off mass of the abrasionring portion after the test/pile portion mass of the abrasion ringportion before the test×100%

Examples 6 to 13

A spun-dyed polylacted textured filament yarn, a pile yarn and a carpetwere manufactured as follows, and the evaluation results are shown inTable 2.

[Manufacturing of a Spun-Dyed Polylacted Textured Filament Yarn]

Using the manufacturing apparatus shown in Table 1, a spun-dyedpolylacted textured filament yarn was manufactured. Polylacted chips(polymer of lactide monomer consisting of L-lactide 98 mass % andD-lactide 2 mass %, weight-average molecular weight: 140,000, relativeviscosity: 3.2; melting point Tm: 170° c.) in the amount of 100 massparts were thrown in through the polylacted chips inlet 10 and carbonblack 25 mass % mixed master batch in the amount of 4 mass parts wasthrown in through the coloring agent inlet 11. While expelling anyremaining air, they were melt-blended in the biaxial extruder 12 at 230°C. The content of the carbon black as a coloring agent was set to 1.0mass %.

The spinning temperature of the spinning heat 14 was set to 225° C., and600 mesh filter was used as the spinning pack 15. Thereafter, they wereextruded through a nozzle having a total of 64 holes each having acircular cross-section (round circular cross-section) into three packsfilament yarns simultaneously.

The spun filaments were cooled and solidified with quench air (20° C.70%) from the quench air blowing apparatus 16 to thereby obtain a totalof 192 polylacted multi-filaments each having a circular cross-section.

After the cooling and solidifying them, a water emulsion type lubricanthaving a concentration of 15 mass % for polylacted filament yarns wasapplied to the filaments with the lubricant applying apparatus 17, andthen the filaments were received by the non-heated receiving roller 1rotating at a rotational rate of 423 m/min. Then, the filamens werecontinuously pre-heated with the pre-heating roller 2 set to arotational rate of 426 m/min. and a temperature of 70° C. Thereafter,the spun filaments were introduced to the draw roller 3 set to arotational rate of 444 m/min. and a temperature of 105° C. and theheat-set roller 4 set to a rotational rate of 2,000 m/min. and atemperature of 123° C. to execute drawing. The draw ratio was 4.5.

Next, the heat-set spun filaments were introduced in the texturingdevice 5 to execute crimping processing by heated and pressurized air of115° C. and 0.6 MPa and then cooled on the cooling drum 20. Then, thetextured filament yarns were subjected to entangle processing of 32counts/m with the entangle processing device 21 and wounded with windingtensile tenacity of 0.05 cN/dtex and at the rotational rate of 1,737m/min.

The obtained spun-dyed textured synthetic filament yarn was a circularcross-sectional filament yarn (circular in cross-section) having a totalfineness of 1,674 dtex/192 filament (a filament fineness: 8.7 dtex),relative viscosity of 3.0, tenacity of 2.36 cN/dtex, elongation of52.5%, hot water shrinkage ratio of 3.5%, and dry heat crimp ratio of12.8%.

[Manufacturing a Pile Yarn]

Using two obtained spun-dyed textured polylacted filament yarns, lowertwisting: Z180 T/m and upper twisting: Z180 T/m were executed to obtaina twisted yarn. Thereafter, the twisted yarn was subjected to a heatedair treatment at 115° C. with a Sussen heat-set device to fix the twiststo thereby obtain a pile yarn for a tufted carpet.

[Manufacturing a Carpet]

Using a tufting machine, the aforementioned pile yarn was tufted in aprimary base fabric for a tufted carpet made of a polyester nonwovenfabric while changing conditions of the gauge (needle number/1 inch:2.54 cm), stitch (stitch number/10 cm), average pile length (mm), andpile portion weight per unit area (g/m²) to thereby produce tufted pileoriginal fabric of Examples to 8 shown in Table 1 under each standard.

Next, EVA pre-coating was performed on the rear surface of the pile yarntufted original fabric to seal it. Thereafter, a polyethylene resinsheet as a backing agent was adhered on the rear surface of the originalfabric together with a polyester needle punched nonwoven fabric layer(secondary base fabric, weight per unit area: 400 g/m²) to obtain atufted carpet.

The loftiness and the Taber abrasion test results of these carpets areshown in Table 2.

TABLE 2 EXAMPLE 6 7 8 9 10 11 12 13 Carpet surface Pile shape — CL CL CLPC PC PC PC PC Gauge 2.54 cm/needle  1/10   1/10   1/10 1/10 1/10 1/101/10 1/10 number Stitch Stitch number/ 52 52 46 52 52 46 40 32 10 cmAverage pile mm 12/7 9.5/5 8.5/4 12 10 9 6.5 6.5 length Pile weightg/cm² 2060 1570 1360 2200 1840 1460 920 730 per unit area CarpetLoftiness — ⊚ ◯~⊚ ◯ ⊚ ◯~⊚ ◯ ◯ ◯ characteristics Abrasion Mass % 20.919.1 21.0 18.4 15.8 19.6 24.3 26.8 resistance CL: cut & loop PC: Plaincut

Comparative Examples 4 to 8 Manufacturing of a Spun-Dyed PolylactedTextured Filament Yarn

A black spun-dyed polylacted textured filament yarn was manufactured inthe same manner as in <Example 6> except that a nozzle having 32 holeseach having a Y-cross-section was used.

The obtained black spun-dyed textured synthetic filament yarn was aY-shaped cross-sectional filament yarn having a total fineness of 1,105dtex/96 filament (a filament fineness: 11.5 dtex) and the degree ofdeformation of 2.2. The relative viscosity (RV) was 3.0, the tenacitywas 1.67 cN/dtex, the elongation was 32.2%, the hot water shrinkageratio was 4.6%, and the dry heat crimp ratio was 14.0%.

[Manufacturing a Pile Yarn]

Using three obtained black spun-dyed textured polylacted filament yarns,lower twisting: Z180 T/m and upper twisting: Z180 T/m were executed toobtain a twisted yarn. Thereafter, the twisted yarn was subjected to aheated air treatment at 115° C. with a Sussen heat-set device to fix thetwists to thereby obtain a pile yarn for a tufted carpet.

[Manufacturing a Carpet]

Using a tufting machine, the aforementioned pile yarn was tufted in aprimary base fabric for a tufted carpet made of a polyester nonwovenfabric while changing conditions of the gauge (needle number/1 inch:2.54 cm), stitch (stitch number/10 cm), average pile length (mm), andpile portion weight per unit area (g/m²) to thereby produce tufted pileoriginal fabrics of Comparative Examples 4 to 8 shown in Table 3 undereach standard.

In the same manner as in Examples, EVA pre-coating was performed on therear surface of the pile yarn tufted original fabric. Thereafter, apolyethylene resin sheet as a backing agent was adhered on the rearsurface of the original fabric together with a polyester needle punchednonwoven fabric layer (secondary base fabric, weight per unit area: 400g/m²) to obtain a tufted carpet. The loftiness and the Taber abrasiontest results of these carpets of <Comparative Examples 4 to 8> are shownin Table 3.

TABLE 3 COMPARATIVE EXAMPLE 4 5 6 7 8 Carpet surface Pile shape — PC PCPC PC PC Gauge 2.54 cm/needle 1/8 1/8 1/8 1/8 1/8 number Stitch Stitchnumber/ 53 53 53 44 33 10 cm Average pile mm 15 12 8 8 7 length Pileweight g/cm² 2010 1610 1070 890 600 per unit area Carpet Loftiness — ⊚◯~⊚ ◯ ◯ ◯ characteristics Abrasion Mass % 33.3 32.5 34.2 37.5 40.8resistance CL: cut & loop PC: Plain cut

Next, concrete examples of the third invention will be explained.Characteristics of each spun-dyed polylacted textured filament yarn weremeasured based on the aforementioned measuring methods. The loftinessand the abrasion resistance of the obtained tufted carpet were evaluatedbased on the following evaluation methods.

[Loftiness]

When observed the carpet from the right above, the carpet was visuallyobserved in a state in which the base fabric could be observed via thegaps of the pile surface and evaluated as follows: “⊚” denotes that thebase fabric could not be observed; “∘” denotes that the base fabriccould be hardly observed; “Δ” denotes that the base fabric could beobserved to some degree; and “x” denotes that the base fabric could beclearly observed.

[Abrasion Resistance Evaluation]

The evaluation of the abrasion resistance of the carpet was executedaccording to the Taber type abrasion test (defined by the Taber typeabrasion test (JIS L1096.8.17.3 (2004 Edition)), where an H-18 abrasionring was used, and the number of abrasion was 5,000 times). That is,using an H-18 abrasion ring, a load of 9.8 N was applied to eachabrasion ring and a test stand was rotated 5,000 times to wear thespecimen. The abrasion amount of the pile yarn was measured. From thefollowing equation, the Taber abrasion amount (mass %) was obtained.

Taber abrasion amount (mass %)=pile dropped-off mass of the abrasionring portion after the test/pile portion mass of the abrasion ringportion before the test×100%

Examples 14 to 17 Manufacturing of a Spun-Dyed Textured PolylactedFilament Yarn Made from Plant-Derived Material

Polylacted chips (polymer of lactide monomer consisting of L-lactide 98mass % and D-lactide 2 mass %, weight-average molecular weight: 140,000,relative viscosity: 3.2, melting point Tm: 170° C.) in the amount of 100mass parts were thrown in through the polylacted chips inlet 10 of themanufacturing apparatus shown in FIG. 1 and carbon black 25 mass % mixedmaster batch in the amount of 4 mass parts were thrown in through thecoloring agent inlet 11. While expelling any remaining air, they weremelt-blended in the biaxial extruder 12 with vents 13 at 230° C. Thecontent of the carbon black as a coloring agent was set to 1.0 mass %.

The spinning temperature of the spinning heat 14 was set to 225° C., and600 mesh filter was used as the spinning pack 15. Thereafter, they wereextruded through a nozzle having a total of 64 holes each having acircular cross-section (round circular cross-section) into three packsfilament yarns simultaneously.

The spun filaments were cooled and solidified with quench air (20°C.×70%) from the quench air blowing apparatus 16 to thereby obtain atotal of 192 polylacted multi-filaments each having a circularcross-section.

After the cooling and solidifying them, a water emulsion type lubricanthaving a concentration of 15 mass % for polylacted filaments was appliedto the filaments with the lubricant applying apparatus 17, and then thefilaments were received by the non-heated receiving roller 1 rotating ata rotational rate of 423 m/min. Then, the filaments were continuouslypre-heated with the pre-heating roller 2 set to a rotational rate of 426m/min. and a temperature of 70° C. Thereafter, the spun filaments wereintroduced to the draw roller 3 set to a rotational rate of 444 m/min.and a temperature of 105° C. and the heat-set roller 4 set to arotational rate of 2,000 m/min. and a temperature of 123° C. to executedrawing. The draw ratio was 4.5.

Next, the heat-set spun filaments were introduced in the texturingdevice 5 to execute crimping processing by heated and pressurized air of115° C. and 0.6 MPa and then cooled on the cooling drum 20. Then, thetextured filament yarns were subjected to entangle processing of 32counts/m with the entangle processing device 21 and wounded with windingtensile tenacity of 0.05 cN/dtex and at the rotational rate of 1,737m/min.

The obtained spun-dyed textured polylacted filament yarn was a circularcross-sectional filament yarn (circular in cross-section) having a totalfineness of 1,674 dtex/192 filament (a filament fineness: 8.7 dtex),relative viscosity of 3.0, tenacity of 2.36 cN/dtex, elongation of52.5%, hot water shrinkage ratio of 3.5%, and dry heat crimp ratio of12.8%.

[Spun-Dyed Textured Synthetic Filament Yarn Made from Petroleum-DerivedMaterial]

As a spun-dyed textured synthetic filament yarn made frompetroleum-derived material, a spun-dyed textured polyester filament yarnwas used. The black spun-dyed textured polyester filament yarn hasproperties of tenacity: 3.22 cN/dtex, elongation: 35.1%, hot watershrinkage ratio: 3.5%; and dry heat crimp ratio: 23.7 W at the trilovalcross-section of fineness: 1,471 dtex/96 filaments (a filament fineness:15.3 dtex).

[Manufacturing a Pile Yarn Made from Plant-Derived Materials]

Using obtained two black spun-dyed textured polylacted filament yarnsmade from plant-derived materials, lower twisting: Z180 T/m and uppertwisting: Z180 T/m were executed to obtain a twisted yarn comprising twofilament yarns. Thereafter, the twisted yarn was subjected to a heatedair treatment at 115° C. with a Sussen heat-set device to fix the twiststo thereby obtain a pile yarn made from plant-derived materials for atufted carpet.

[Manufacturing a Pile Yarn Made from Petroleum-Derived Materials]

Using obtained two black spun-dyed textured polyester filament yarnsmade from petroleum-derived materials, lower twisting: Z180 T/m andupper twisting: Z180 T/m were executed to obtain a twisted yarncomprising two filament yarns. Thereafter, the twisted yarn wassubjected to a heated air treatment at 180° C. with a Sussen heat-setdevice to fix the twists to thereby obtain a pile yarn made frompetroleum-derived materials for a tufted carpet.

[Manufacturing a Carpet]

Using a tufting machine, the aforementioned two types of pile yarns weretufted alternatively in a primary base fabric for a tufted carpet madeof a polyester nonwoven fabric while changing conditions of the gauge(needle number/1 inch: 2.54 cm), stitch (stitch cm), average pile length(mm), and pile portion weight per unit area (g/m²) to thereby producetufted pile original fabrics of Examples 14 to 17 shown in Table 4 undereach standard.

Next, using SBR latex, pre-coating was performed on the rear surface ofthe pile yarn tufted original fabric. Thereafter, using a polyethyleneresin sheet as a backing agent, a tufted carpet was manufactured.

The loftiness and the Taber abrasion test results of these carpets areshown in Table 4.

TABLE 4 Example 14 15 16 17 Carpet surface Pile shape — PC PC PC PCGauge 25.4 cm/number 1/10 1/10 1/10 1/10 of needle Stitch Stitch number/52.5 52 45 40 10 cm Average mm 12 9 8 6.5 pile length Pile weight g/m²2030 1540 1220 960 per unit area Carpet Loftiness — ⊚ ◯~⊚ ◯ ◯characteristics Abrasion mass % 16.8 15.0 13.5 17.5 resistance CL: Cutand loop PC: Plain cut

Examples 18 to 22 Manufacturing a Pile Yarn Made from Plant-DerivedMaterials

In the same manner as in <Example 14>, a black spun-dyed polylactedtextured filament yarn was manufactured except that a nozzle having 32holes each having a Y-cross-section was used.

The obtained black spun-dyed textured synthetic filament yarn made fromplant-derived materials was a triloval cross-sectional filament yarnhaving a total fineness of 1,105 dtex/96 filament (a filament fineness:11.5 dtex) and the degree of deformation of 2.2. The relative viscosity(RV) was 3.0, the tenacity was 1.67 cN/dtex, the elongation was 32.2%,the hot water shrinkage ratio was 4.6%, and the dry heat crimp ratio was14.0%.

[Manufacturing a Pile Yarn Made from Plant-Derived Materials]

Using three obtained black spun-dyed textured polylacted filament yarnsmade from plant-derived materials, lower twisting: Z180 T/m and uppertwisting: Z180 T/m were executed to obtain a twisted yarn. Thereafter,the twisted yarn was subjected to a heated air treatment at 115° C. witha Sussen heat-set device to fix the twists to thereby obtain a pile yarnmade from plant-derived materials for a tufted carpet.

[Manufacturing a Pile Yarn Made from Petroleum-Derived Materials]

Using obtained two black spun-dyed textured polyester filament yarnsmade from petroleum-derived materials, lower twisting: Z180 T/m andupper twisting: Z180 T/m were executed to obtain a twisted yarncomprising two filament yarns. Thereafter, the twisted yarn wassubjected to a heated air treatment at 180° C. with a Sussen heat-setdevice to fix the twists to thereby obtain a pile yarn made frompetroleum-derived materials for a tufted carpet.

[Manufacturing a Carpet]

Using a tufting machine, the aforementioned two types of pile yarns weretufted alternatively in a primary base fabric for a tufted carpet madeof a polyester nonwoven fabric while changing conditions of the gauge(needle number/1 inch: 2.54 cm), stitch (stitch number/10 cm), averagepile length (mm), and pile portion weight per unit area (g/m²) tothereby produce tufted pile original fabrics of Examples 18 to 22 shownin Table 5 under each standard.

In the same manner as in Examples 14 to 17>, using SBR latex,pre-coating was performed on the rear surface of the pile yarn tuftedoriginal fabric. Thereafter, using a polyethylene resin sheet as abacking agent, a tufted carpet was manufactured.

The loftiness and the Taber abrasion test results of these carpets of<Examples 18 to 22> are shown in Table 5.

TABLE 5 Example 18 19 20 21 22 Carpet surface Pile shape — PC PC PC PCPC Gauge 25.4 cm/number 1/8 1/8 1/8 1/8 1/8 of needle Stitch Stitchnumber/ 53 53 53 44 33 10 cm Average mm 15 12 8 8 7 pile length Pileweight g/m² 1900 1560 1110 940 700 per unit area Carpet Loftiness — ⊚◯~⊚ ◯ ◯ ◯ characteristics Abrasion mass % 24.1 24.0 15.0 23.4 28.9resistance CL: Cut and loop PC: Plain cut

Reference Examples 1 to 8

(1) Manufacturing a carpet made of pile yarns 100% plant-derivedmaterials

[Spun-Dyed Textured Polylacted Filament Yarn Made from Plant-DerivedMaterials]

The same spun-dyed textured polylacted filament yarns as in <Examples 14to 17> were used. The obtained back spun-dyed textured polylactedfilament yarn was a circular cross-sectional filament cross-sectionalfilament yarn (circular in cross-section) having a total fineness of1,674 dtex/192 filament (a filament fineness: 8.7 dtex),relative-viscosity of 3.0, tenacity of 2.36 cN/dtex, elongation of52.5%, hot water shrinkage ratio of 3.5%, and dry heat crimp ratio of12.8%.

[Manufacturing a Pile Yarn Made from Plant-Derived Materials]

The same spun-dyed textured polylacted filament yarns as in <Examples 14to 17> were used. That is, using obtained black spun-dyed texturedpolylacted filament yarns made from plant-derived materials, lowertwisting: Z180 T/m and upper twisting: Z180 T/m were executed to obtaina twisted yarn comprising two filament yarns. Thereafter, the twistedyarn was subjected to a heated air treatment at 115° C. with a Sussenheat-set device to fix the twists to thereby obtain a pile yarn madefrom plant-derived materials for a tufted carpet.

[Manufacturing a Carpet]

In the same manner as in <Examples 14 to 17>, using a tufting machine,the aforementioned pile yarn was tufted in a primary base fabric for atufted carpet made of a polyester nonwoven fabric while changingconditions of the gauge (needle number/1 inch: 2.54 cm), stitch (stitchnumber/10 cm), average pile length (mm), and pile portion weight perunit area (g/m²) to thereby produce tufted pile original fabrics ofReference Examples 1 to 8 shown in Table 6 under each standard.

In the same manner as in <Examples 14 to 17>, using SBR latex,pre-coating was performed on the rear surface of the pile yarn tuftedoriginal fabric. Thereafter, using a polyethylene resin sheet as abacking agent, a tufted carpet was manufactured.

The loftiness and the Taber abrasion test results of these carpets of<Reference Examples 1 to 8> are shown in Table 6.

TABLE 6 REFERENCE EXAMPLE 1 2 3 4 5 6 7 8 Carpet surface Pile shape — CLCL CL PC PC PC PC PC Gauge 2.54 cm/needle  1/10   1/10   1/10 1/10 1/101/10 1/10 1/10 number Stitch Stitch number/ 52 52 46 52 52 46 40 32 10cm Average pile mm 12/8 9.5/5 8.5/4 12 10 9 6.5 6.5 length Pile weightg/cm² 2060 1720 1410 2100 1720 1400 1010 700 per unit area CarpetLoftiness — ⊚ ◯~⊚ ◯ ⊚ ◯~⊚ ◯ ◯ ◯ characteristics Abrasion Mass % 41.838.3 41.9 36.7 35.6 39.2 48.6 51.5 resistance CL: cut & loop PC: Plaincut

Reference Examples 9 to 13 (2) Manufacturing a Carpet Made of Pile Yarns100% Plant-Derived Materials

[Spun-Dyed Textured Polylacted Filament Yarn Made from Plant-DerivedMaterials]

The same spun-dyed textured polylacted filament yarns as in <Examples 18to 22> were used. The obtained black spun-dyed textured syntheticfilament yarn made from plant-derived materials was a trilovalcross-sectional filament yarn having a total fineness of 1,105 dtex/96filament (a filament fineness: 11.5 dtex) and the degree of deformationof 2.2. The relative viscosity (RV) was 3.0, the tenacity was 1.67cN/dtex, the elongation was 32.2%, the hot water shrinkage ratio was4.6%, and the dry heat crimp ratio was 14.0%.

Hereinafter, in the same manner as in <Examples 18 to 22>, manufacturingof [a pile yarn made from plant-derived materials] and [manufacturing ofa carpet] were performed. The loftiness and the Taber abrasion testresults of these carpets are shown as <Reference Examples 9 to 13> inTable 7.

TABLE 7 Reference Example 9 10 11 12 13 Carpet surface Pile shape — PCPC PC PC PC Gauge 25.4 cm/number 1/8 1/8 1/8 1/8 1/8 of needle StitchStitch number/ 53 53 53 44 33 10 cm Average mm 15 12 8 8 7 pile lengthPile weight g/m² 2010 1660 1180 1000 700 per unit area Carpet Loftiness— ⊚ ◯~⊚ ◯ ◯ ◯ characteristics Abrasion mass % 51.9 42.8 51.5 75.1 81.6resistance CL: Cut and loop PC: Plain cut

This application claims priority to Japanese Patent Application No.2005-258632 filed on Sep. 7, 2005, Japanese Patent Application No.2005-286444 filed on Sep. 30, 2005, and Japanese Patent Application No.2005-286452 filed on Sep. 30, 2005, the entire disclosures of which areincorporated herein by reference in their entireties.

It should be appreciated that the terms and descriptions herein are usedonly for explaining embodiments of the present invention, and thepresent invention is not limited to them. The present invention permitsany design modifications within the scope of the present inventiondefined by the appended claims unless they deviate from its spirit ofthe present invention.

INDUSTRIAL APPLICABILITY

A spun-dyed textured polylacted filament yarn of the first invention anda spun-dyed textured polylacted filament yarn obtained by themanufacturing method of the first invention can be preferably used as,for example, a constituent yarn of a carpet. For example, it can be usedas a constituent yarn for a roll carpet, a piece carpet, a tile carpet,an automobile carpet and an option carpet, and a household rug/mat. Incases where a pile of a carpet is constituted by the spun-dyed texturedpolylacted filament yarns of the first invention, the pile configurationis not specifically limited, and can be in any form such as, e.g., a cutpile, a loop file, and a cut-and-loop file. Furthermore, it can be usedas a constituent yarn for, e.g., a woven carpet, a knitted carpet, anembroider carpet, and an adhesive carpet. The carpet constituted byusing the spun-dyed textured polylacted filament yarns of the firstinvention can contribute to global environment protections since it canbe decomposed by microorganisms, etc., when discarded after the use.

1. A spun-dyed textured polylacted filament yarn, comprising a texturedpolylacted filament yarn, wherein the textured polylacted filament yarncomprises a filament having an approximately circular or circularcross-section and has a relative viscosity of 2.5 to 3.8, wherein thetextured polylacted filament yarn contains a coloring agent in an amountof 0.01 to 3 mass %, and wherein the textured polylacted filament yarnis 1.75 to 3.5 cN/dtex in tenacity, 35 to 60% in elongation, 500 to3,500 dtex in total fineness, 2.5 to 25 dtex in a filament fineness, 2to 8% in hot water shrinkage ratio, and 5 to 25% in dry heat crimpratio.
 2. The spun-dyed textured polylacted filament yarn as recited inclaim 1, wherein the filament has an approximately circular or circularcross-section having a degree of deformation less than 1.5.
 3. Thespun-dyed textured polylacted filament yarn as recited in claim 1,wherein the coloring agent is at least one pigment selected from thegroup consisting of an inorganic pigment and an organic pigment.
 4. Acarpet in which the spun-dyed textured polylacted filament yarn asrecited in claim 1 is used as at least a part of constituent yarn. 5.(canceled)
 6. A method for manufacturing a spun-dyed textured polylactedfilament yarn, comprising the steps of: obtaining spun filaments byextruding a polylacted resin composition containing a coloring agent anda polylacted resin and having a coloring agent content of 0.01 to 3 mass% and a relative viscosity of 2.5 to 3.8 through a spinning nozzle intofilaments each having an approximately circular or circularcross-section and a degree of deformation less than 1.5, cooling thefilaments with quench air, and then coating the filaments withlubricant; drawing the spun filaments at a draw ratio of 3 times to 6times with a draw roller set to 70 to 125° C.; heat-setting the drawnspun filaments with a heat-set roller set to 100 to 150° C.; givingcrimps to the heat-set drawn spun filaments by bringing a heated fluidof 90 to 160° C. into contact with the heat-set drawn spun filamentsusing a texturing device; and cooling the textured spun filaments afterthe crimping step to a temperature lower than a glass transitiontemperature of the polylacted polymer.
 7. The method of manufacturing aspun-dyed textured polylacted filament yarn as recited in claim 6,wherein the following relational expression is met:30° C.≧S−R≧—10° C. where “S” is a temperature of the heat-set roller,and “R” is a temperature of the heated fluid in the texturing device. 8.The method of manufacturing a spun-dyed textured polylacted filamentyarn as recited in claim 6, wherein the drawn spun filaments areheat-set with a heat-set roller set to a temperature range of 100° C. toa softening point of the polylacted polymer.
 9. The method ofmanufacturing a spun-dyed textured polylacted filament yarn as recitedin claim 6, wherein crimps are given to the heat-set drawn spunfilaments by bringing the heated fluid set to a temperature range of 90°C. to a softening point of the polylacted polymer into contact with thefilaments using the texturing device.
 10. The method of manufacturing aspun-dyed textured polylacted filament yarn as recited in claim 6,further comprising a step of subjecting the textured spun filaments wentthrough the cooling step to an entangle process using a entangleprocessing device.
 11. A spun-dyed textured polylacted filament yarnmanufactured by the manufacturing method as recited in claim
 6. 12. Acarpet in which at least a part of constituent yarns of the carpet isconstituted by the spun-dyed textured polylacted filament yarn asrecited in claim
 11. 13. A carpet using a spun-dyed textured polylactedfilament yarn comprising a filament having an approximately circular orcircular cross-section as a pile yarn.
 14. The carpet as recited inclaim 13, wherein the spun-dyed textured polylacted filament yarn meetsall of the following characteristics (1) to (7): (1) a filament has anapproximately circular or circular cross-section having a degree ofdeformation less than 1.5, wherein the degree of deformation isexpressed by a ratio (B/A) of a diameter B of an circumscribed circle ofthe filament cross-section to a diameter A of a inscribed circle of thefilament cross-section; (2) relative viscosity (RV) is 2.5 to 3.8; (3)tenacity is 1.75 to 3.5 cN/dtex; (4) elongation is 35 to 60%; (5) afilament fineness is 2.5 to 25 dtex; (6) hot water shrinkage ratio is 2to 8%; and (7) dry heat crimp ratio is 5 to 25%.
 15. The carpet asrecited in claim 13, wherein the pile yarn comprises a single yarnand/or two or more doubled and twisted yarns made of a non-twistedand/or twisted spun-dyed textured polylacted filament yarn.
 16. Thecarpet as recited in claim 13, wherein an average length of pilesforming a carpet is 5 to 15 mm, and a weight per unit area of the pilesis 500 to 3,000 g/m².
 17. The carpet as recited in claim 13, wherein anabrasion amount of pile yarns forming a carpet measured by a TABERabrasion test (abrasion ring: H-18, abrasion number: 2,500 times) is 5to 30 mass %.
 18. A carpet according to claim 13 further comprising aspun-dyed textured synthetic filament yarn as a pile yarn, wherein anabrasion amount of the pile yarn forming a carpet measured by a TABERabrasion test (abrasion ring: H-18, abrasion number: 5,000 times) is 5to 30 mass %.
 19. The carpet as recited in claim 18, wherein thespun-dyed textured synthetic filament yarn is at least one of spun-dyedtextured synthetic filament yarn selected from the group consisting of aspun-dyed textured polyester filament yarn, a spun-dyed textured nylonfilament yarn, and a spun-dyed textured polypropylene filament yarn. 20.The carpet as recited in claim 18, wherein the spun-dyed texturedpolylacted filament yarn meets all of the following characteristics (1)to (7): (1) a filament has an approximately circular or circularcross-section having a degree of deformation less than 1.5, wherein thedegree of deformation is expressed by a ratio (B/A) of a diameter B ofan circumscribed circle of the filament cross-section to a diameter A ofa inscribed circle of the filament cross-section; (2) relative viscosity(RV) is 2.5 to 3.8; (3) tenacity is 1.75 to 3.5 cN/dtex; (4) elongationis 35 to 60%; (5) a filament fineness is 2.5 to 25 dtex; (6) hot watershrinkage ratio is 2 to 8%; and (7) dry heat crimp ratio is 5 to 25%.21. (canceled)
 22. The carpet as recited in claim 18, wherein thespun-dyed textured polylacted filament yarn is made of plant-derivedmaterial, and the spun-dryed textured synthetic filament yarn is made ofpetroleum-derived material.